General introduction for working principle of screening
In mining process, screen plays the unique role. There are vibrating screen, high
efficiency vibrating screen. Generally speaking, the screening process can be
defined as follows: Make broken materials of different particle sizes pass
through the single-deck or multilayer screen surface with uniform screen mesh
and then classify the materials into different levels of gradation. In theory,
the particle sizes bigger than the sieve mesh are called screen overflow, while
the particle sizes smaller than the sieve mesh are referred to as screen
underflow.
The screening process of broken materials can be composed of two stages, that
is, fine particles passing through the material layer formed by superfine
particles and reaching the screen surface, and fine particles passing through
the sieve mesh. If you want to complete the two stages mentioned above, the most
fundamental condition required is that there should exist relative motion
between the materials and the screen surface. Consequently, the screen box
should be with corresponding motion characteristic. On the one hand, it can keep
the material layer in loose condition, and on the other hand, it can help to
remove the coarse particles stuck in the sieve mesh and meanwhile make the fine
particles successively pass through the screen.
Technology comparison between an impact crusher and hammer crusher
As we know, impact crusher
and hammer crusher
both are the main equipment in stone production line. They have
similarities and differences. As to the advanced technology, let's make a
comparision.
The unique working principle of impact crusher overcomes the many defects of
hammer crusher. At first, the discharging particles of impact crusher mainly are
granular, while hammer crusher does maybe have much power. In addition, impact
crusher can effectively deal those materials with moisture, thus it can reduce
the jam phenomenon.
When the material contain much moisture, the feeding chute and impact board
of impact crusher can be equipped with heating device, prevent the bond of
material. And impact crusher dont need equip with the bottom sieve plate, it
just can effectively avoid the block phenomenon. However, hammer crusher cant
adopt heating way to prevent the bond of material, and need equip the bottom
sieve plate, thus it just increase the possibilities of jam.
Impact crusher not only can apply on soft material, but also apply to the
very large hardness material. The plate hammer of impact crusher adopts the
mechanical firm structure and fixed to the rotor, thus when the rotor move, it
has more rotator force. Relative to hammer crusher, the rotor of impact crusher
has more momentum, suitable to crushing the more hard material and saving
energy.
Impact crusher can adjust the discharging particle convenient, and the
adjusting range is extensive. Impact crusher can adjust the discharging particle
by so many ways, such as adjust rotor speed, impact plate and the space of
grinding cavity, etc. the gap adjustment can be done through mechanical or
hydraulic way, and hydraulic adjustment system can easy operate the button or
long distance control system to accomplish the space adjustment. While impact
crusher adjust the discharging particle only by changing bottom sieve plate.
Wear-resistant parts of impact crusher are so few compared with hammer
crusher, and higher use ratio of metal.
The replacement of spare parts is so simple, thus the cost of maintenance
will less. The impact crusher rotor just installed six plate hammers, and
replacing a set of plate hammer just needs short time. And the replacement of
bottom grinding cavity also need about ten minutes, and then which greatly
reduce the cost of infection and maintenance. However, the hammer of hammer
crusher has more than 100 pair; it will spend a lot of time and labor power to
replace a set of hammer, the cost of inspection and maintenance is higher than
impact crusher. Replacement of bottom sieve plate is also trouble.
In addition to impact crusher and hammer crusher, there are jaw crusher, cone crusher, roll
crusher, sigle-stage roll crusher, mobile crushing plant. Facing different
working circumstance, proper crushers can make greatest profits.
In recent years, India's economic is developing fast, urgently request to
speed up the construction of infrastructure. Then It is proposed to large demand
of grinding equipment. It is reported that India's demand for grinding equipment
will increase substantially from 2011. In the next five years, the demand will
be more strong growth in China, is the optimal period for developing grinding
equipment industry in Indian Market.
In recent years India grinding equipment sales are in 1.5 billion to $2
billion, the annual rate of growth between 20% ~ 30%. Presently, the concrete
products utilization rate is less than 1%, so in the next five years, the usage
will grow by 30% and concrete equipments have a great potential market.
The Indian government regard infrastructure as one of the key economic
development. Road construction equipment, crane, a vast market of elevators,
material conveying equipment and heavy-load transportation tool demand will have
certain growth. With the advantage of good quality grinding mill equipment,
Henan Hongxing Machinery will expand the market in India. Now, our Raymond mill, high
strength pulverizer, micro powder mill, ball mill, vertical
mill are launched and welcomed at home and abroad. In international market, it's
the key to grasp every chance.
The methods to select the hands of mining machinery: vibratory feeder
The vibratory feeder is used to transfer the large size materials and
granular materials from hopper to receiving device uniformly, periodically and
continuously in the production flow and to feed materials into the crusher
continuously and uniformly also to screen the materials in the sandstone
production line.It is widely used to match the crushing and sieving equipments
in many industries including metallurgy, coal mine, mineral dressing, building
material, chemical, grinding, etc. Without vibrating feeder, it is like that
one without hands to eat. And also, vibrating feeders are expensive machinery,
so we should take serious and cautious consideration on selection to make sure
the cost and future using.
Two steps are required in selecting the proper feeder for a specific
installation:
1. Obtaining basic application information.
2. Following a selection procedure.
Information Required:
1. Largest size material in feed.
2. Approximate analysis of material size.
3. Desired capacity.
4. Type and description of material.
5. Type of installation.
Selection Procedure
Step 1. From Chart I, select feeder width factor appropriate to the
application. Multiply the factor by the size of the largest piece in the feed to
obtain minimum feeder width.
Step 2. Check the minimum width determined in Step 1 with capacity in Chart
II. Note required slope angle to produce desired capacity. If necessary,
increase feeder width to obtain desired capacity. There may be several
combinations of slope and width which will produce the capacity required.
Factors such as headroom, depth of bed, unit cost, width of conveyor or
crusher and future capacity requirements should be considered prior o final
selection.
Step 3. Feeder lengths should not be shorter than that needed to retain
material at its angle of repose on the feeder pan when the feeder is shut
down... plus a 6 to 12 safety factor to prevent possibility of free flow.
Feeder length must be sufficient to convey the required distance.
Step 4. Select slope angle to best suit required capacity from Chart II and
length to retain material angle of repose from illustration B. A sketch drawn to
scale showing slope and material repose angles will assist in showing
relationship between feeder length and slope.
Step 5. When a four-sided hopper is used, refer to Chart I and illustration B
to determine minimum hopper throat opening. Simply multiply the largest material
lump size by the hopper throat opening factor to obtain this figure.
Step 6. Make final feeder selection. Often, more than one size and type of
feeder will satisfy the application requirements. The final selection will
depend on various factors including:
a. Size and type of crusher when feeding directly to crusher.
b. Conveyor width when feeding in line with material travel.
c. Size of material handled and loading on feeder.
d. Hopper capacity required. With a larger feeder there is more hopper
capacity.
e. Headroom available. A sloped feeder normally requires more headroom.
f. Amount of grizzly length required to remove fines.
g. Price. A smaller or lighter duty feeder is less expensive.
h. Future requirements. Will a larger crusher or conveyor be installed? Will
plant capacity be increased?
Hongxing grinder machines perform excellently in crushing coal gangue
Coal gangue is researched and used as a solid waste with great quantity and
also a recycling resource, in construction, metallurgy, light industry and
chemical industry. Coal gangue was activated by means of calcination in seven
temperature ranges.
Nowadays, coal gangue is mainly employed to make general building materials,
high-grade building ceramic tiles, coating materials and fillings, high
value-added products, and stuffing in road building.The ceramic tile has been
one of building's decorate materials since a long time. Kaolinminerals is raw
material of ceramic tile.According to statistics, output of our country ceramic
tile achieves 171.5 million square meters, account for 2/5 of world's output in
2002 year. With developing science technology improving and administer level
advancing, quality and variety of our country ceramic tile has very changed. But
clay raw material of ceramic tile increase losing of cultivated land, we must
look for new raw material of ceramic tile as quickly as possible.
Owing to compare to clay, raw material of kaolinminerals-high-aluminum-coal
gangue possess higher hardness, therefore, traditional crushing technics will
bring about consuming more energy and rising cost of tile.The microwave
technology can reduce crushing strength of coal gangue, milling expenditure,
economy energy, reducing cost.This paper indicates that traditional milling
technics need 4.00 hours when coal gangue is milled to 325 without microwave
radiation. The milling only needs 55.00 minute after microwave radiation 5.00
minute. So, microwave radiation pre-crushing coal gangue raw material can save
1/2 of electrical fee in actual project per year.
Under the situation of lacking energy, mining machinery equipment manufactory
is paying more attention on high efficiency and energy saving. Henan Hongxing
Machinery takes notice on update and promotion of mining machinery equipment,
and its HGM series medium-speed micro-powder making machine is the new
generation equipment. The HGM series grinder is one kind of fine powder and
superfine powder processing machine, and is used for coal gangue, marble, chalk,
barite, bentonite, rock phosphate, rectorite etc. It has many advantages: high
efficiency, long life of quick-wear part, high safety and reliability, super
fine powder, environmental protection and so on. The whole equipment of HGM
medium-speed grinder consists of hammer crusher, bucket elevator, storage bin,
electric magnetic feeder, powder collector, pulse dust removal, main engine,
powder concentrator, high pressure fan, silencer.
Henan Hongxing Machinery is the professional manufacturer of powder making
machines. Through 20 years of researches and development, there are a series of
powder making machines, HGM series micro-powder grinder, MTW series Europen
trapezium grinder, LM series vertical grinder, super pressure trapezium grinder,
high pressure roll grinder.
Where to seek whole equipment for barite? - Hongxing is here.
Barite is kind of non-metallic mineral products which take the barium sulfate
(BaSO4) as the main component. Barite is regarded as the common mineral of
barium, and it is major component is barium sulphate. It arises from the
hydrothermal veins, limestone, and clay deposits because of limestone
weathering. Barite can be used as zincolith (commonly known as lithopone), and
in addition applied in chemical industry, paper making, and textile packing.
China's total supply of barite in 2500 to 3000 tons, all from domestic
production for. Domestic consumption of barite in 1300 was about 1,200 tons, of
which oil and gas exploration for the 700 to 800 million tons, 60% of total
consumption; for barium chemical products 400 to 500 million tons, accounting
for about 30%; accounting for about 10%. China is the world's largest exporter
of barite. 90's annual export volume of barite and its products is generally 150
to 200 tons. Barite and the barium salt in 1996 2.058 million tons exported, the
export amount of 121 million, of which 1.86 million tons barite.
Barite powder fineness requirements typically require 325 mesh -1800 mesh,
for the fineness range, Hongxing manufacturing barite production line including
MTW Medium Speed Trapezium provide barite grinding mill , MTW European version
of the Trapezium Mill, HGM and other variety of ultra-fine powder mill New
milling machine equipment, the main model for grinding barite, barite ore can be
from 25 cm below the ore processed through the pipeline 325mesh -2500mesh
powder, ensure powder, powder sub-index to meet clients' demands.
Barite powder is white or gray crystalline powder, is an important mineral
containing barium, chemically inert, good stability, acid, density, hardness,
high specific gravity, high whiteness, can absorb the harmful rays (x-ray and
γ-rays), etc., a glass gloss, non-magnetic and non-toxic. Thus, widely used in
chemical, paint, rubber, glass, paper, medicine and other fields, according to
the latest statistics, the size of the use of more than 2000 items. high
specific gravity, high whiteness, can absorb the harmful rays (x-ray and
γ-rays), etc., a glass gloss, non-magnetic and non-toxic. Thus, widely used in
chemical, paint, rubber, glass, paper, medicine and other fields, according to
the latest statistics, the size of the use of more than 2000 items.
Barite crusher designed by Hongxing, Big size barite into crusher, after vibrating feeder in turn into jaw crusher, impact crusher, then will pass
through the sieve vibrating screening, get different sizes of finished product
barite to satisfy different materials demands.
If you are interested in one or more products and want to learn more details,
welcome to visit Henan Hongxing Mining Machinery Co., Ltd. for your barite
crushing line inquiries!
Industrial diesel engines run and develop in machinery industry
As we know, the price of petroleum and diesel is increasing fast, which
affects many development of industry.
Industrial diesel engines are any engines that are used for industrial
purposes that run on diesel. Industrial diesel engines are used to power a major
portion of industrial machinery, from motorbikes to bulldozers, generators, and
even forklifts and trucks. They range in size from a few pounds to a few tons,
with a various amount of power.
The use of diesel engines is mandated by several large organizations. All
NATO machinery for example, runs on either diesel or aviation grade kerosene. At
the current level of technology, fossil fuels, and especially diesel are the
most economical and convenient means of supplying power to a variety of
equipment and even backup generators.
All industrial diesel engines can be either air cooled or water cooled. The
smallest engines for residential purposes will typically provide about 10kW and
cost a few thousand USD. These smaller scale engines power much of the mobile
machinery we see around us on a daily basis, such as trucks, farm equipment,
small boats, stationary process machinery, earth movers, and so on.
The medium scale industrial diesel engines can provide levels between a few
hundred kW and a few thousand kW and are sold for prices in usually the
thousands of dollars. These types are used in larger machinery such as larger
mining equipment, oil rigs, trains, large boats, military equipment, and much
more.
The largest of industrial diesel engines provide 10,000 to 80,000 kW, sold in
the millions of dollars, and are used for ultra heavy equipment, electric power
generation, and the largest of ships. Large industrial engines can be up to 49
feet side and run on low grade diesels. In places such as China, where there is
a high demand for de-centralized power sources, these types of engines are often
utilized.
Industrial engines are classified in terms of their speed, or RPM (Rotations
Per Minute). High RPM engines are normally used for the lighter, more common
applications, such as trucks and other types of land equipment.
Medium RPM engines are generally used for power generation. Low RPM ranges,
and high torque engines are used for the biggest type of equipment, such as
marine equipment and applications.
For the most part, industrial diesel engines can vary in terms of size and
performance. Chances are, you've either seen or used industrial equipment at
some point in time. Although they cost a lot of money, they are the way to go
with bigger equipment for getting the job done right the first time.
Just like mining machinery industry, it is also affected by the phenomenon of
price rise. Jaw crusher market
is changed and innovated because of the rising price of steel materials.
The specific surplus disposal options for mining machinery enterprises
Consignment involves hiring an equipment dealer, typically the company that
sold you the equipment, to market and sell your surplus equipment.
The consignment process:
a. Consignee (broker) and Consignor (owner) agree upon market value of
equipment.
b. Execute or sign off on the consignment agreement.
c. Equipment is listed/marketed by broker.
d. Buyer submits a purchase offer on equipment.
e. Equipment is sold and broker collects payment; broker retains commission;
remaining funds sent to Consignor or owner of equipment; equipment is released
to buyer.
For this effort, the consignee or broker will charge a commission. Fees vary,
depending on the asset type but typically range from 8-20 % of the final sale
price. For example, on a $100,000 asset you can expect to pay $8-20,000 in
commissions.
Auctioneers
This method has been around forever and in fact can be traced back to 500
B.C. There are many types of auction formats but we will specifically address a
public auction for selling heavy equipment. In this format, the bidders'
identities are not hidden and anyone is welcome to attend the auction or to
place bids via the internet.
The equipment auction process:
a. Auction house or re-marketer appraises your assets and provides seller a
proposal outlining their commission structure. The percentage is based on the
amount and the value of the equipment a seller places at auction. Auction
companies sometimes partner with sellers by offering a guarantee to the seller
on what will net or be paid.
b. Location of auction determined. Large lots are subject to a lower
commission and if it warrants the auction can be held on seller's site. For
smaller lots, a higher fee is payable and the owner is required to transport the
assets to the closest auction yard.
c. Auction agreement is finalized.
d. Auctioneer sets date and equipment is marketed.
e. Bidders register and viewing/inspection of assets take place.
f. The numbered asset is called and bidding takes place. Bidders can be
physically present or place their bid on-line via an internet portal with the
asset awarded to highest bidder.
g. Payment is collected by Auctioneer, fees retained or deducted from sale
price with residual given to owner.
h. Asset is then released to buyer with conditions of sale attached.
Auctions can be risky as returns are not guaranteed, however, the process
encourages competition and the hope is two bidding parties want the asset enough
to pay fair market value or more.
Inside Sales (Sell it yourself)
Another attractive option is the disposition of the asset using your own
personnel. As in any business transaction, by selling to an end user and cutting
out the middle person you would expect to achieve a better return.
How to:
a. Use a reputable online equipment portal that ranks high with all major
search engines. For example, Google 'used mining equipment' and find a high
ranking portal.
b. Take digital pictures highlighting areas of the asset you would want to
see if you were the buyer.
c. If applicable, collect the maintenance history and the equipment/component
hours.
d. Record the make, model, serial number and any other equipment
specifications
e. Determine a selling price. If you are unsure of the market value of your
asset you can pay for an appraisal, request a free one from the OEM dealer, and
surf various internet portals reviewing sales history or asking prices of like
or similar assets. Reviewing the original purchase price documentation will also
help you ascertain a bench mark.
f. Post your assets using content rich relative keywords. In real estate it
is location, location, location, with mining equipment it is details, details,
details which will ensure you generate quality leads which will result in a
sale.
In addition to the financial benefits, there are many advantages to selling
your surplus equipment, such as, retaining control of the negotiation process
and disposition time-line. By selling the asset with an 'As is, Where is'
condition you also eliminate further financial risk by no longer having to
transport or dismantle the asset to auction.
As part of the due diligence process, a majority of the 'sell it yourself'
tasks should be done regardless of your final disposition decision, therefore,
attempting to sell it yourself is the next logical step to take and is
definitely worth the effort.
Crane industry expands and develops all over the world, South Africa as an example
Development of China's construction crane started in the 20th century, the
fifties or sixties, the late seventies through the eighties the introduction,
absorption and self-development phase since the nineties, the domestic
construction industry after crane wind and rain, since the sales began in 1993,
along decline until the market rebounder in 1999. In recent years, construction
machinery market continued to blow, the industry rarely appeared in the general
economy, industry profits and sales every year an average of over 35%. At the
same time, mining machinery industry has made great progress. Such as jaw crusher, cone crusher, Raymond mill have great market
and development space.
Not only in China, as to South Africa, crane industry is more and more
flourishing. There are some reports on this issue.
Heavy lift and relocation specialist Vanguard's R70-million investment, the
GTK 1100 crane, has arrived in South Africa. The crane is the only one of its
kind in Africa and is the seventh in the world.
The crane is designed and manufactured by Grove Cranes, a subsidiary of
Germany-based crane manufacturer Manitowoc.
Vanguard director Andrew Nordengen says that the crane arrived in the country
on April 21. The first lift it performed was during the installation of a 2-MW
wind turbine at the Coega industrial development zone, in Port Elizabeth.
However, Vanguard is positive that the GTK 1100 will spark the interest of
the mining industry, as it can be used in any craning application of up to 100 t
at 120 m hook height.
'The crane has a number of advantages which are beneficial for the mining
industry,' says Nordengen.
The GTK 1100 has a lifting height of 140 m, a maximum capacity of 100 t, a
maximum working radius of 56 m and can be erected in comparatively small spaces,
by crane standards, as it has a footprint of 18 m × 18 m.
The other components of the tower unit are four spreaders, with a tubular
lattice design, intended for bracing at the top of the tower. Each spreader
includes a tensioning cylinder and a vibration damper.
The GTK 1100 only requires four trailers for transportation to its intended
site and can be assembled in four to six hours. The GTK 1100 is also a far more
cost-effective and flexible crane in terms of site establishment, adds
Nordengen.
'This crane is one of the most sophisticated mobile cranes in the world. It
has a number of unique advantages, such as enhanced site flexibility and reduced
project costs, providing new opportunities for the South African engineering and
construction industry. In addition, it provides the added advantage of being
able to lift ultraheavy loads in small spaces,' he explains.
Nordengen says that Vanguard has supplied heavy lifting and specialised
transportation services to a variety of mines.
'The most recent has involved the transportation of three cold boxes and
exchangers for mines in Zambia and Namibia. The cold boxes were transported on
Vanguards modular trailer and then lifted and rotated 90o into position using a
strand jacking system,' he concludes.
New technologies and products for fine grinding at home and abroad
Platinum Mile, a South African tailings treatment company recently awarded a
contract to Deswik Mining Consultants for the provision of two Deswik 2000s for
its operation in Rustenberg. The two fine grind vertical Deswik mills will
operate on separate circuits with the mills producing 100 and 60 t/h (dry) from
an ore feed of D-90 50-60μm to a product of D-90 25um. The two mills have been
designed to operate at 6.5 and 11.2 kWh/t respectively.
Deswiks scope of work on the project includes the manufacture, assembly,
installation, commissioning and operational training of the Platinum Mile staff.
It is planned that the Deswik mills will be installed and commissioned in
July.
Deswik provides a complete design and construction service for its patented
vertical fine grinding technology. This innovative technology can be used in
concentrators and also as a solution for dump re-treatment projects. The Deswik
mill is used to grind feed material to a specific particle size and
distribution, ensuring improved performance of downstream metallurgical leach or
flotation processes. It has proved to be a highly efficient machine for the
reduction of metal bearing ores resulting in greater liberation of primary
material from much higher froth flotation and leach recovery rates. The mill
uses 50% less installed power than its competitors, and delivers up to 100% more
throughput per cubic metre of mill capacity, the company claims.
It is a vertical stirred bead mill that offers a unique media/product
separation system operating at high efficiency with simple operation and
maintenance. Low noise operation, high degree of automation and data collection
and compact footprint are other advantages. The Deswik mill can produce particle
sizes from a D-50 of 200 μm down to 0.1 μm. This is achieved over a range of
some 200 different products at energy consumption levels as low as 3 kWh/t.
New technologies in fine grinding offer substantial energy savings and AMIRA
project P1003 seeks to provide the hard data which would enable companies to
make decisions on which of these new technologies is most appropriate for them
and what improvements they might expect.
In China, we have pushed the policy of 'green industry''environmental
protection''low carbon life'. With these calls, many industry enterprises make
great and many innovations and inventions to promote the product quality and
environmental protection usage. High pressure micro-powder grinder, superfine
crusher, ultra-fine impact
crusher appear.
Also, opportunities exist to improve liberation of cleaner feed without
harmful chemistry (achieving better than traditional grades that improve
smelting throughput) and to reduce primary grinding on high tonnage streams and
do more regrinding on rougher and scavenger concentrates. These would achieve
lower overall energy consumption by inert regrinding.
Gold mining industry has marched into environment friendly industry
Green Industry is producing environment friendly products or products which
should help improve nature conditions to better. And also during working process
cause minimal damage to environment. Green industry ought recycling waste of
working process (cutting) and recycling waste energy (heat). Green industry
ought to reach wasteless working process. The green industry is focused on
eliminating or significantly reducing dependence on oil, green house emissions,
and toxins. With the more and more serious environment issues, green industry
has become the top industry. It applies in all industry, mining machinery
industry, chemical industry, road construction, agriculture and so on.
Gold mining is one of the great mining industry. Nowadays, gold mining
industry goes into green industry.
Mining for gold has traditionally been viewed as a toxic business that harms
the environment leaving mercury and other harsh chemicals in the atmosphere.
However, this view is beginning to change as gold mining practices turn to fair
trade. The new fair trade standards set social, environmental, and economic
measures to eliminate child labor and minimize the use of toxic chemicals such
as mercury and cyanide. The major goal of this movement is to avoid the negative
impacts that mining causes in the environment while also aiming to help the
millions of people who depend on the gold mining industry for employment.
Many companies are already beginning to produce under the fair trade standard
promising customers that their gold products are ethically sourced and produced
with no mercury or cyanide. Training miners to become more environmentally
responsible has been a key objective for fair trade companies that hope to
create more sustainable business practices. After all, extending the useful life
of a gold mine is not only advantageous to the environment but also to the
business itself. Many fair trade gold businesses in South America are going a
step further by increasing the salaries of their workers, almost doubling the
previous average pay. This will dramatically help the workers and their families
who depend greatly on the gold mining industry.
As of now, fair trade gold is being produced in only four countriesBolivia,
Colombia, Ecuador, and Peru. Other countries in South America have yet to join
the fair trade gold movement including Venezuela who recently nationalized their
gold industry. That may change within the next two years as mines in Latin
America, Asia, and Africa are set to join the fair trade standard. A growing
number of retailers will also join the movement by beginning to sell their gold
jewelry under the fair trade label.
Turning the gold mining industry into a clean, environmentally friendly
practice will not happen overnight as only 15 percent of the global gold supply
is produced under fair trade. Right now, fair trade only covers small-scale
mining projects and has limited impact on the worlds gold supply. New business
practices need to start somewhere and the fair trade mining practice has begun
nevertheless.
Mining is the leading work, mine hoist is one of its arms
The world of mining has more than seven thousand producing mines around the
globe and every year we can find that there are more quickly progressing and
being developed. These mines give us the raw materials needed for the
construction, manufacturing and industries of chemicals and the majority of the
minerals of energy upon which our everyday life is so needed of. So, it's first
and important to grasp the ways to select the mining machinery equipment.
Bringing the hoist to a controlled, smooth stop after a total power failure
is the most important brake function. This has not been a problem for drum
hoists at depths to approximately 3000 feet, nor is it a problem with Koepe
hoists where the system is either in balance when empty or maximum out of
balance when loaded. On a double drum hoist at depths below 3000 feet, however,
the rope weight and conveyance, whether loaded or empty, can create such a wide
variance of braking requirements that a more sophisticated brake control is
required.
Here is a guide to calculate how to size a mine hoist while you know the
desired capacity (TPH) and depth for vertical shaft. The main problem in
selecting a hoist for a given capacity and depth is deciding on the proper skip
load (payload). A larger load hoisted at slower speeds requires less horsepower,
but at the expense of increased rope diameter which, in turn, increases the drum
diameter, gearing, etc. In selecting a skip size, therefore, it is helpful to
know the relationship between skip load, speed, and capacity for the given
depth.
The cost of the headframe, skips, loading pockets and ropes enters into the
economics when selecting skip loads, but these cost changes are relatively
small. (Skip sizes can be varied within limits without changing the shaft
selection.) We are not attempting to make an economic comparison between drum
and Koepe schemes in this manual to select one over the other involves a
complex study which should include the complete hoisting plants. If your skip
weight factor is known, use it rather than 0.75. To determine proper friction
hoist skip weight.
There are several emergency braking arrangements available: varying braking
pressure with depth and/or hoisting direction; firing off a sequence of valves
applying braking as needed according to a feedback rate; setting the brake
rapidly until the feedback system dictates that rate must be held until
stopping.Should the actual speed of the conveyance be greater than required by
the reference signal, the governor applies the brake in proportion to the
difference in signals. If the actual conveyance speed is less than the preset
reference signal, the governor releases the brake.
To achieve the precision of final powder through the effective diameter of a grinding mill
Grinding mills are very important in mining industry. Through the mills, we
can get proper and wanted kinds of powders. Of course, if you'd like to make the
final products more accurate, the effective diameter of a grinding mill is the
key.
The effective diameter of a grinding mill is the diameter inside lining;
i.e., the net diameter. In this case, the mill under consideration is a new
installation so liners will be roughly 3 thick and the net diameter will be 6
less than the diameter inside the shell. Since no diameter has been specified,
investigate a range to find the most suitable. From the table the values of A
are:
For a net diameter of 106 (3200mm) ..................................... A
= 63.5
For a net diameter of 116 (3205mm) ..................................... A
= 79.3
For a net diameter of 126 (3810mm) ..................................... A
= 97.5
For a net diameter of 136 (4114mm) ..................................... A
= 118.5
Step 3: Most overflow discharge mills operate with 35 to 45 percent charge.
An average value is 40%. The value of B from the table for a wet overflow mill
at 40% is as follows: b = 5.02
Step 4: Speed was not specified, so a range of speeds should be investigated
to find the most suitable. From the table the values of C are as follows:
For 68% of critical speed ........... C = 0.1583
For 72% of critical speed ........... C = 0.1724
For 76% of critical speed ........... C = 0.1878
Step 5: Solving for the length of the mill with 026 net diameter, 40%
charge and 68% of critical speed required to draw 1400 HP:
Do you know that: how to finger up the charge volune of a ball mill or rod mill?
In physics, the charge of a volume is commonly described by a quantity called
the charge density or the charge distribution. When the electric field that
arises from the charge distribution exhibits a volumetric symmetry, a handy
relationship known as Gauss's Law may be used to calculate the charge
distribution of the volume.
The charge volume of a ball or rod mill is expressed as the
percentage of the volume within the liners filled with balls or rods. When the
mill is stationary, the charge volume can be quickly obtained by measuring the
diameter inside the liners and the distance from the top of the mill inside the
liners to the top of the charge. The percentage loading or change volume can
then be read off the graph in Figure 3 or can be approximated from the following
equation:
% loading = 113 126 H/ D
where H is distance from top of mill inside of lining to top of charge and D
is diameter of mill.
Maximum power is drawn by a mill when the charge occupies approximately 50%
by volume. However, as seen in Figure 4, the power curve becomes very flat in
the range above 45%. As a result, mills are seldom run with charge levels
greater than 45%.
In rod mills, the charge is swollen by particles of feed which separate the
rods. If the mill is shut down immediately after the feed is shut off, the
charge level will be greater than if the mill had been ground out prior to
shutdown. Because of this, rod mills are normally operated with a 32 to 40
percent charge by volume. In operation, this becomes a 40 to 50 percent charge,
with a bulk density considerably lower than that of stacked rods.
Ball mill charge becomes
measurably swollen only when there is a buildup of large unground material in
the ball mill or when the density of the pulp in a wet mill is extremely high.
Although these conditions are seldom encountered, it is recommended that ball
mills be ground out prior to shutdown for measurement of the charge level.
The development wind of water conservancy blows up the crusher industry
It is known that, crushers are used in various industry, such as chemicals,
metallergy, coal mine, gold and road construction. And also they can serve for
water conservancy. Between them, the relationship of 'mutual benefits'
exists.
For recnet years, there are many positive reports on water conservancy
development. Water Resources budget implementation progress will accelerate in
the second half, especially for infrastructure projects will be the focus.
Industry sources believe that by tightening the impact of the first half of
capital investment is not in place affecting the water, in the second half of
these issues will be resolved, large-scale water conservancy construction
investment projects will be started.
Experience with conventional, hydraulic sand and gravel aggregate demand is
very large, pre-production and living facilities projects, including
infrastructure and construction of road construction, and later the hub
construction of the main building, we need a lot of sand and gravel aggregate
supply. Sand and gravel aggregate industry will undoubtedly continue to benefit.
Only strict customs, in order to cast the qualified projects. Large-scale water
production capacity of the equipment requirements and other conditions are very
harsh, and the gravel field production equipment, crusher selection will
directly affect product quality.
Learned that the water conservancy construction equipment tender, clearly
defined, engaged in sand and gravel production line configured more than 3 years
and 3 years, with construction of the Nissan production capacity of 1000-10000
tons of sand and gravel aggregate companies to bid.
Since ancient times, water conservancy construction is the protection of
national stability, along with the motor car derailment, House crunchy, the
collapse of the bridge collapse and a series of shabby appearance, quality of
infrastructure has been put on the agenda, especially in water conservancy
construction, gravel bone material is the high demands, high-quality sand and
gravel aggregate processing must use high-quality crusher, sand making
equipment, which relates to the use of project quality and project results, but
also a high degree of responsibility for peoples property.
Water conservancy project started to drive the development of major
industrial sand and gravel aggregate, sand and gravel aggregate industry is not
only an beneficiary in the development,crusher enterprises also benefit from the
water conservancy project especially famous crusher manufacturers, but adequate
companies want a slice, it depends on the strength!
Solutions to deal with the blockage problem of crushers of Hongxing Chapter
Crusher are used as the common and usual equipment in mining industry, and
certainly there are many problems when runnig. The crushers will suddenly work
when the phenomenon of blockage, then the crusher block, how to deal with the
problem? Hongxing will give your some tips.
Firstly, crusher block is the continuous use of the common faults that may
exist in the design of the organism itself, but more are caused by the use of
improper operation.
Secondly, feed too fast, the load increases, is caused by blockage of one of
the reasons. So we use the crusher must pay attention to the feeding process,
the meter pointer deflection angle should always pay attention to big problems,
if more than the rated current, indicating that the motor overload, overload a
long time, it will burn out the motor. This happens immediately reduce or close
the door material, can also change the way feed, by increasing the feed to
control the fluxes. Feeders with manual and automatic, the user should choose
the right according to the actual feeder.
Users should always pay attention to the relevant operation of crusher, which
would accordingly reduce the clogging phenomenon crusher．
To make "win-win" throughout the development of China construction machinery industry
Any industry, any equipment is anticipating high efficiency and low cost,
especially for expensive construction machinery industry. The enterprise profits
are anticipated more and more. Construction machinery industry is not only
important to promote the people's livelihood relies on the construction, but
also the achievement of the industry, rapid development of effective protection,
so the development of construction machinery industry is also a priority in the
other. That is why the 'high efficiency' has become the measure an important
indicator of construction machinery products, but now, construction machinery,
'efficiency' is still up in the high-energy-based implementation, which also led
to our construction also in large amounts of energy, manufacturing a wide range
of pollution. How to reach both efficiency and energy-saving in construction
machinery industry, which should be taken into consideration.
Construction machinery industry is a combination of technology, capital and
labor, in recent years as China's construction machinery industry, the
increasing size of the market expansion and our continued efforts to strengthen
infrastructure, economic market segments made higher requirements, including not
only technical, intelligence, including energy saving, environmental protection
and other factors. Nowadays, energy saving has become a hot topic in our
society, it seems to be no energy saving construction machinery industry is also
related to development of the market to catch the express train, the urgent need
to efficiency, energy saving, green, environmentally friendly direction of
transformation. Many energy saving concept has also been applied to construction
machinery products, such as 2009, in the country for the first time introduced
the concept of hybrid energy-saving machinery to study, and developed a new type
of China's first jaw crusher,
crushing than the traditional machine 30% energy efficiency by 25%. It also
confirmed the construction machinery enterprises are moving toward the goal of
energy saving efforts.
After 50 years development, China construction machinery industry forms an
important industry which produces products of 18 categories, more than 4500
specifications and types, and meets the basic demand in domestic market and has
quite a scale and flourishing development vitality. Although there are some
performances, but still in its infancy. China's construction machinery industry
is currently facing energy conversion efficiency is low, the operation is
backward, and serious environmental pollution problems, which gives the energy
saving industry has posed a serious challenge. At present, China's primary
energy consumption has more than 3.2 billion tons of standard coal, crude oil
dependence on foreign imports to reach 55%. Oil consumption is the main area of
petrochemicals, transportation and engineering machinery. Construction
machinery, especially the broken machinery industry, oil consumption is an
important aspect can not be ignored.
But compared with foreign competitors, China construction machinery
enterprises still have some problems as follows, they are: big gap of control
technology; corresponding parts( spare parts, components) non-reaching standard;
insufficient consideration of man-machine engineering; less research and
development input. It is the key for construction machinery industry to
adjusting the product structure in the development process.
In addition, we also take into account environmental issues, the traditional
engineering machinery products have been far from meeting the requirements of
air quality at this stage, to long-term sustainable development, and only
continuous technological upgrading and innovation that the future of
construction machinery essential factor is the environmental protection
industry. In addition, competition in the international market which is not
often due to emissions standards, exports have been seriously hampered. From
this green energy has become China's construction machinery industry, the
problem can not be ignored. But we also see in the domestic construction
machinery enterprises are active in-depth study of a new generation of energy
saving, environmental protection equipment, more and more construction machinery
manufacturers have focused mostly on 'energy-saving''intelligent' two key
word.
Demand and growth rate of construction machinery products have close relation
with GDP and investment scale of infrastructure construction, industry boom
situation is related to the growth rate of investment in fixed assets with
synchronized positive correlation. During the '10th Five Years', consumption
amount of China construction machinery occupied 1.9% of the whole social fixed
asset averagely per annum. The growth rate of fixed assets investment will slow
down during the '11th Five Years', market capacity will expand relatively
insufficiently, and the industry will develop toward rationality
gradually.
It's imperative to reinforce the foreign mineral resources utilization
Mineral resources is the most important foundation our country's economic
construction and social development, it has vital position in the national
economy and security. At the same time, any resource maybe use out. Todays,
energy and resource expolitaion is the serious issue to talk about.
In case the supply of mineral resources disruptions, it will pose a serious
threat on economic, social and national security. However since the 1990s, many
mineral resources consumption growth has approximated or exceed the national
economic development speed. The economic growth made a large demand of mineral
resources. A resource analysis data recently shows, in 2010 ,mineral oil, gas,
aluminum and iron, copper, gold, nickel, sulfur, boron, uranium, phosphorus,
potassium, chromium, asbestos are unable to satisfy domestic demand, by the year
2020, The shortage of China mineral resources will be increased to 39 kinds.
Analysts say that in the coming decades, with Chinese industrialization and
economic globalization, China will become the world's most important mineral
resources consumption country. In the coming decades, comparing with main
mineral demand in our country at present, the main mineral reserves will appear
serious shortage. And mineral resources in Chinese economic and social security
is decline, the paradox of resource bottleneck of contradiction is becoming more
and more serious. To implement the strategy of 'going out' is dispensable, we
should make full use of both domestic and international markets, to satisfy
domestic economic development needs.
No modernized countries in the world can make all mineral resources and raw
materials self-sufficient. In recent years, China's oil, iron ore, copper metal
importing dependence are becoming more and more serious, particularly oil and
iron ore. Long-term excessive dependence on imported is both economic problems
and national security concerns. For the long-term development, only based on the
resource security, the national security is guaranteed. Implementing the
strategy of 'going out' will extend more space and wider range of areas and at a
higher level participating in international economic and technological
cooperation and competition domestic and abroad. Make full use of two kinds of
resources, two 'markets', build all-round, mineral resources and sustainable
supply system and improve mineral resources sustainable development of national
economy is the issue we should concern.
We Henan Hongxing Machinery are the famous manufacturer of mining machinery
equipment in China and have been titled 'China famous machinery brand'. We have
passed through ISO9001:2000. Our always focus on technology innovations, product
design, development, production, installation and maintenance. At any time,
clients are always the first.
For ore dressing process, there are two ways: flotation process, magnetic
process. Magnetic separator is
used in magnetic procell. It applies to wet magnetic separation of materials
below 3mm such as the magnetite, pyrrhonitite, roasted ore, limonite，ilmenite.
Also used for coal, non-metallic minerals, building materials' remove working.
Magnetic line of the magnetic separator uses high quality ferrite materials
or compound with rare-earth magnet, the average magnetic induction is 100～600
MT, we can provide downstream, semi-current, counter-current, a number of
different forms magnetic separator according to the users' need. You can use
them in industries like mining, and smaller versions are widely-used in
scientific labs to process some kinds of samples. Numerous companies make
magnetic separators for assorted applications, there are some variations
intended for website visitors to select from,jaw crusher, according to the
application and needs. This sort of products are which is available from
companies which are experts in industrial processing equipment, therefore it may
be ordered completely from manufacturers, where individuals have customized
needs.
An elementary magnetic separator is made up of magnet of some sort. As
materials are passed below, over, through, or round the magnetic separator, it
attracts undesirable impurities, pulling them out and cleansing the process
stream. Magnetic separators might be ferromagnetic or paramagnetic, according to
the needs, and in many cases materials will likely be passed through both
varieties of magnetic separators. They may differ in proportions from tabletop
separators found in labs to massive drums found in recycling facilities.
One of several common uses of a magnetic separator will be the eliminating
so-called tramp metal,Magnetic Separator, undesirable iron that may foul a
procedure stream. Magnetic separators may also be employed to remove materials
which may damage or foul equipment, inside a pre-processing step. Separators may
also be used to sort various metal, using a group of separators varying in
intensity to get out strongly and weakly magnetic materials at different
times.
Like other devices used in processing materials, a magnetic separator must be
properly maintained and operated as directed in order to be effective.
Maintenance includes clearing the separator to remove magnetic materials it has
collected, along with periodically oiling moving parts. In the case of
electromagnets, it is also necessary to make sure that emergency shutoffs and
other safety features are in operational condition, so that the magnet can be
turned off in the event that a problem develops on the production line.
