diamond processing flow chart of beneficiation
World demand and production of diamond both for gem and industrial purposes has increased nearly five-fold during the past 25 years. Improved mining and recovery methods together with the discovery and development of new fields has enabled mining operations to fill the growing demands. Producing areas in Canada, South Africa, South West Africa, The Congo Republic, Angola, Ghana, Tanganyika and Sierra Leone account for over the bulk of world production.
In mining, diamonds are recovered mainly from alluvial deposits which vary widely in character, often cemented; and usually contain large quantities of clay or a sticky slime fraction from near zero to about 50%. Substantial production also comes from Kimberlite pipes and dikes (Blue Ground), a basic igneous breccia, considered generally to be the originating source for nearly all diamonds. Diamonds have a specific gravity up to 3.52and are associated with minerals such as magnetite, ilmenite, garnet, tourmaline, spinel, rutile, pyrite, quartz and other minerals which due to their specific gravity makes separation from the diamonds difficult and affects the ratio of concentration obtainable through gravity methods. Since the value per ton of diamondiferous gravel seldom exceeds one metric carat per ton with an average of less than 0.3 carat, a high ratio of concentration, in the order of 1: 5,000,000 or higher, is necessary.
Many recovery methods are used and methods vary depending on the location, size and nature of the deposit. The methods include production by natives using simple hand pans to more complex mechanical means employing washing, screening, stage crushing, clear water and puddle panning, heavy media separation, jigging, attrition and differential grinding, magnetic and/or electro-static separation, flotation, grease tabling and hand sorting. Certain operations use one or more field plants to supply a central plant for reconcentration and final sorting.
This flowsheet is typical for small to medium tonnages of alluvial feed (5 to 30 tons per hour). Such material is often cemented and requires crushing by either jaw or gyratory crushers. In this flowsheet a trommel screen, with a scrubbing section, is used to break down clay and cemented fractions, before screening and rejection of the oversize to waste. The trommel undersize, 1, is fed to centrifugal diamond pans in series.
Diamond pans were developed in South Africa and have been highly successful and widely used in the recovery of diamonds. Their use for the separation of other minerals has been limited and inefficient.
A diamond pan is a shallow, flat bottomed circular pan with an inner well about 0.3 of the pan diameter and several inches lower in height than the outer pan wall. A vertical shaft is mounted to rotate in the center to which radial horizontal arms are attached above the pulp level in the pan. Tines extend downward from the radial arms and are adjustable to clear the pan bottom. These tines are triangular and so spaced and mounted on the radial arms to plow material on the pan bottom outward. The feed entry is tangential to the outer wall while the tailings discharge is through a weir in the center well. In operation the tangential entry of the feed combined with the stirring action of the tines causes a vertical swirl to the mass. The condition created in the pan simulates the heavy media process in that the lighter materials remain in suspension and are carried down the vortex to the center discharge weir while the heavier particles settle through the swirling mass to be plowed outward on the bottom to a concentrate discharge outlet in the outer wall. Feeds containing a high amount of clay and fine sands give the most effective results, however, many pans operate on feeds containing little or no clay or fines with reduced but still satisfactory recoveries. Capacity of diamond pans is normally 5 to 6 tons per square foot of effective area per 24 hours and require 1 to 1 horsepower per ton of feed. Ratios of concentration vary, usually from 10:1 to 50:1 depending on the amounts of heavy minerals associated with the diamonds. Recoveries up to 97% are sometimes possible.
The diamond pan concentrates in Flowsheet No. 1 are elevated to a trommel screen for sizing to eliminate 16 mesh undersize and to produce four size ranges each going to a Duplex Mineral Jig for further concentration.Mineral Jigs have proven to be very efficient in diamond treatment with recoveries near 100% being reported. The jigs are equipped with 2 mm bedding screens. No artificial bedding is added in most operations since the pan concentrates contain sufficient heavy minerals to form adequate bedding. A 2-mm hutch concentrate is produced from the jigs which are discharged to locked containers before being removed to the final recovery section. The 2-mm concentrate retained on the jig screens is removed by hand at intervals as necessary and are hand sorted for recovery of the diamonds. All phases of concentrate handling are done under conditions to insure security. All launders, jig compartments and concentrate collection points are covered, locked or protected to prevent theft.
This flowsheet was developed for diamond recovery from Kimberlite ore as mined and with properly sized equipment is suitable for tonnages up to 50 tons per hour. The mined ore is crushed to 3 followed by screening and secondary crushing to 1. A picking belt is sometimes employed between crushing stages for removal of waste rock and possible recovery of large diamonds, but this step is generally considered uneconomical. Few, if any diamonds are broken in the crushing operations, as they are usually smaller than the crusher openings, and break free from the matrix without damage. The crushed ore goes to a bin for storage and for controlled feeding to the recovery circuit. A trommel screen with scrubbing sections is used to break down any soft portion of the ore before screening. Oversize material is reduced to 1 with a spring roll crusher and then joins the trommel undersize to feed a centrifugal diamond pan. The flowsheet shows one pan, however, several pans in series are sometimes found to be more effective when the ore contains high percentages of heavy minerals. The pan tailings are elevated or dewatered and conveyed to another screening and crushing step to provide a3/8 feed to asecondary diamond pan. The tailings from the secondarypan are elevated and screened to produce a + 1/8 fraction as a final tailing, and a 1/8 product which passes to a Duplex Mineral Jig for recovery of any small diamonds remaining. The concentrates from the primary and secondary pans are each separately fed to two Duplex Mineral Jigs in series for reconcentration. The use of Mineral Jigs in series on the unclassified feed eliminates the necessity of classification or screening to produce sized feedfractions often necessary when plunger type jigs are used. The ratio of concentration on jigs in this service ranges from 10:1 upward depending on the amounts of heavy minerals in the pan concentrates. Feed rates vary from 200 to 1000 pounds per square foot of compartment area per hour.
The final recovery of the diamonds from gravity concentrates is accomplished by several steps of reconcentration which differ in many cases due to the amount and nature of the associated gangue minerals. When appreciable amounts of heavy minerals are present the concentrates are sized to give a 1/8 fraction which is dried and passed through magnetic and/or electrostatic separators to eliminate affected materials, before being further reconcentrated on grease tables. The recovery method shown in Flowsheets No. 1 and No. 2 is frequently used when the gravity concentrates are wet screened to three or more size ranges as the feed to separate grease tables and to reject 16 or 28 mesh materials.
The grease tables are of several types being usually either mechanically or electrically vibrated with the movement normal to direction of flow. The decks are made both flat and stepped, being adjustable in slope to give proper flow velocity for the different size ranges of feed. The stepped decks have from 4 to 8 removable compartments or pans each being 8 or more in width by 3 to 4 feet in length, each pan being mounted in steps down the table. Each step is coated with + thickness of a special petroleum grease which is given a surface covering of about 1/16 of another type grease. In operation the sized feed is uniformly fed across the table into a flow of water to carry the material across and down the table steps. The diamonds being non-wettable adhere to the grease while most of the other minerals are carried off the table by the water and are rejected as waste. After 45 to 60 minutes of operation the 1/16 surface layer of grease, together with the diamonds and some other trapped minerals, are scraped from the tables. This grease layer is placed in grease pots having perforated sides. The pots are
covered and placed in boiling water for removal and recovery of the grease. The diamond concentrates after degreasing are hand picked and sorted under diffused light. This final operation is very exacting work and is carried on under close observation and security conditions.
This flowsheet illustrates a more complex diamond recovery method developed in recent years. With variations it can be used to process 100 to 500 tons per hour of Kimberlite ore and is also arranged to handle weathered or soft ores. For the hard ore as mined the flowsheet follows conventional methods of stage crushing and screening to reduce the ore to . The weatheredore is intensely scrubbed to break down the soft fractions and then screened as shown. All the 1 ore is wet screened to produce +10 mesh and 10 mesh sizes. The 1, +10 mesh fraction goes to a heavy media separator from which the sink product, after media screening and washing, goes to concentrate storage. The float product is washed and screened to reject all 3/8 to waste. The +3/8 size is crushed and screened to 3/8 +10 mesh for retreatment to the
heavy media circuit.
All 10 mesh material from the screens ahead of the heavy media process and from the screen following the scrubber is dewatered and wet screened to give a 10 mesh, +16 mesh size range for treatment either by heavy media separation through cyclone separators or by Duplex Mineral Jigs as illustrated.
In the recovery section a number of reconcentration methods are used. Attrition grinding using a light grinding charge at near 40% of critical speed reduces part of the heavy minerals without damage to the diamonds. The mill discharge is screened to eliminate 16 mesh or in some cases 28 mesh and to split the remaining concentrates at about 7 mesh. These two size ranges being treated separately with the 7 mesh going to a mill to effect a differential grind to further reduce the waste materials. This product is wet screened and the oversize is dried, screened to remove dust before passing through an electrostatic separator. The diamond concentrates are then hand sorted. The +7 mesh concentrates are sized, usually to four size ranges, each separately conditioned to remove any coating from the diamonds which interfere with collection on grease tables or grease belts. Grease belts are a recent development and require less attention and labor than grease tables. They are similar to short conveyors and are mounted in a framework so that the slope can be adjusted for correct flow velocity. The concentrates are fed to spread a thin layer over the belt surface down which a stream of water flows. Grease is continually applied to the belt at the upper end and is scraped off at the lower end with the diamonds. The diamonds are degreased and processed by hand sorting.
diamond wash plant ,diamond dms plant- walker mining
Walker mining provide diamond mining machine such as : trommel scrubber,high frequency vibrating screen,jig separator .trommel scrubber is popular in washing clay/mud out the alluvial diamond ore . vibrating screen with high quality pu screen is high efficiency in separating and size different diamond ore .jig separator can concentrate heavy minerals such as diamond.e
Each type has its advantages & disadvantages. Now We make a comparation for more clear
idea. When Checking this document, pls reference to below attachedment:
1. Flowchart of 60TPH Diamond DMS system with jig
1. Total Cost : Price of Diamond DMS system with Ferrosilicon is expensive
expensive than DMS system with Jig
2. Beneficiation process flowchart:
1) DMS system with Ferrosilicon is more complicated than DMS system with Jig, it includes many slurry pipes and slurry pumps, ferrosilicon input ratio and recycling. According to our customer experience at ferrosilicon, it require very professional technical people to check the specific& ratio of ferrosilicon according to diamond ore size and conditions.
2) DMS system with Jig is more simple flowchart, no need ferrosilicon and slurry pipes.
3) 1-25mm diamond concentrate can be separated out by the cyclone in DMS system with Ferrosilicon. The worker is not able to touch with diamond during the whole system processing.
4) In DMS system with Jig, the diamond concentrate will be separated into 2 parts: small diamond will be continously discharged from under screen of jig , on-screen diamond concentrate will stay above screen of jig , after working some months, need to stop jig machine working, and clean out the diamond above screen. In this way, worker may touch the diamond
Description: A mineral composed of pure carbon and the hardest material in nature.
Melting Point: 3550
Density: 3.52 g / cm
Color: Various colors, from colorless to black, colorless is especially good
Appearance: Regular octahedral crystal
Absolute Hardness: 10000-2500
Useful: Arts and Crafts, Cutting tools in industry, etc.,
Distribution: Australia, Congo (Kinshasa), Russia, South Africa, Botswana, China, United States, etc.,
DMS is the abbreviation of dense medium separation, what is one principal type of diamond recovery technologies.And the other one is Rotary Pan plant.Compare to most of the other minerals, the diamond has a much higher specific gravity(density is about 3.52 g / cm ), so DMS is an efficient initial process to separate diamonds from diamond bearing material, after which the material will be further processes for the final diamond recovery.
DMS benefication is a method of separating ore particles according to the specific gravity difference in the medium with specific gravity greater than water. That is to say, minerals with different specific gravity can be separated from each other in direct current or two-phase fluid by the principle of floating and sinking. The specific gravity of the separation medium is between that of the high and low specific gravity mineral particles. The ore particles with small specific gravity float up and the ore particles with large specific gravity sink.
Diamond DMS Plant
Ferrosilicon(an alloy of silicone and iron) will be suspended in water in a DMS plant. Then it will form a fluid that is close to the density of diamonds (3.52 g / cm ). If the ideal density is reached, the diamond bearing material is added to begin the separation process. Due to the gravity, the heavy minerals sink to the bottom, while the lighter material will rise to the top. This is an effectively process to separate diamonds from other material.
Diamond DMS Washing Plant
The commonly used beneficiation methods for diamond are: washing pan, jigging, DMS, X-ray electric, ointment, surface flotation, magnetic, electric, flotation, hand-selected, etc.,
The beneficiation process of primary diamond ore mainly depends on the properties of the raw ore, the scale of the concentrator and other factors. The reasonable technological process mainly considers the protection of diamond crystal from damage or the minimum damage; To determine the reasonable number of crushing sections and the appropriate sorting. The maximum recovery of mineral processing and comprehensive recovery of fine-grained diamond and useful associated minerals are obtained.
The roughing process of diamond placer is simpler than that of primary ore. It does not need multi-stage crushing and grinding and multi-stage separation process, but only needs washing, screening and desliming to enter the separation process.
The concentrate process of diamond placer and primary diamond is basically the same. Generally, the coarse particles (less than 30mm) are treated by X-ray electric separation, grease separation, selective grinding and screening, manual separation and other methods. Surface flotation, magnetic separation, electric separation, selective grinding and screening are used to treat medium size (less than 3mm). Fine grain (less than 1mm) is treated by chemical treatment, froth flotation, magnetohydrostatic separation and heavy liquid separation.
The above flow chat of diamond mining plant contents three parts: washing, crushing and separating. The material enter into the vibrating feeder, through it, the material less than 70mm enter the diamond washing trommel scrubber. After the washing, the particle size greater than 25 is sent to jaw crusher for crushing, and the particle size less than 25 mm is sent to vibrating screen. And then the concentrate of vibrating screen is separated by jig separator.
Diamond DMS Washing Plant Equipment
Trommel Scrubber: Good Effect on Diamond Washing Plant
Diamond ore usually has clay or a large amount of mud, so it is necessary to clean it before separation. Trommel scrubber has a good effect on washing heavy clay or viscous clay. Therefore, it is widely used in diamond washing plants.
High-frequency Vibrating Screen: Screening and Dehydration
After washing the diamond ore, it is necessary to classify the size of the ore. Filter out the size of the waste, and then transport it to other places with a belt conveyor. The particles under the screen will enter the next process.
new technologies in diamond-bearing ore beneficiation
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The development of new technologies in diamond-bearing ore beneficiation is required to increase the stone recovery level and prevent their damage in crushing as well as to reduce the capital and operational expenses of diamond miners.
In recent years, the technology of diamond-bearing ore beneficiation by the Norwegian TOMRA company is increasingly popular and it is based on the use of the X-ray absorption method to detect diamonds. The company produces X-ray (transmission) separators - COM Tertiary XRT - that gradually replace dense medium separation (DMS) plants and X-ray luminescent separators. The COM Tertiary XRT separators use electric X-ray tubes and DUOLINE highly-sensitive innovation touch-sensitive X-ray chambers enabling the use of two independent sensor lines of varying spectral sensitivity. The data transmitted by this chamber is processed by a patented TOMRA Sorting high-speed processor that is able to identify the material atom density irrespective of its thickness. Thus, this technology allows the detection of all diamond types, including the stones with a shell, low luminescent ones and Type II diamonds (having practically no impurities). Besides, the particle size range of the diamonds extracted increases from 25-30 mm to 60 mm and higher. All this results in a high-quality concentrate requiring no additional processing before manual sorting, which reduces the operational expenses markedly. Moreover, the TOMRA separators feature low power and water consumption.
Canadian Lucara Diamond Corp. was one of the first companies to introduce the TOMRA equipment into its technological cycle. In early 2015, Lucara installed six new separators, 150 tph, at the Karowe diamond mine in Botswana, and the success was not long in coming in November, the company recovered its 1,109 carat rough diamond, the second largest rough diamond ever recovered (after Cullinan). After Lucara Diamond, other diamond miners like the Australia-based Lucapa Diamond Company Ltd and Merlin Diamonds Limited started using the TOMRA separators. The Russian diamond miners followed suit in late 2017, the TOMRA separator was installed by AK ALROSA (PAO) at its factory No.14 of the Aikhal Mining and Processing Plant in the Republic of Sakha (Yakutia) to carry out technological testing, and in October 2018, AGD Diamonds (AO) that operates the Grib diamond pipe in the Arkhangelsk Region purchased this equipment and started its commercial use.
The X-ray absorption method was incorporated by other technological enterprises. For example, DebTech (De Beers subsidiary) developed a sorting XRT Coarse Concentrator Plus (CC+) facility, and in late 2018, it introduced it at one of the worlds largest diamond mines Jwaneng in Botswana.
Simultaneously with TOMRA, the Bourevestnik innovation centre (ALROSAs subsidiary) worked on the development of X-ray separators. By 2014, the entre developed RGS-1M and RGS-2 X-ray separators that were also introduced at the ALROSAs enterprises.
To solve the problem of low luminescent diamond extraction, the Russian Irgiredmet research institute developed the method of triboelectric separation based on the electric charges generated during friction. The laboratory and industrial tests of the triboelectric separator showed that its use in the dry conditioning of a diamond concentrate was promising. The Ukrainian Prodekologiya research and production firm manufactures the triboelectric separators (Type EBS-T), however, they found wider use in another sphere - in recycling of polymers, e-wastes and cables.
Severalmaz (PAO) (ALROSA Groups subsidiary) carried out tests of the pilot plant at the Lomonosov Mining & Processing Division (MPD) in the Arkhangelsk Region; the pilot plant is based on the fast-neutron method and was developed by Diamant (OOO) against the order of ALROSA. The plant enables the detection of a diamond in the kimberlite ore without damaging it. The tests allowed determine the optimal plant capacity, 102 kg per hour, and the diamond recovery was 97%. The future Diamant plans included the development of the commercial separator based on the fast-neutron method with the capacity of 30 tons per hour.
The UK-based diamond miner, Gem Diamonds, also concerned about damaging the diamonds during their recovery from the ore has developed and tested their technique of non-mechanical crushing based on the electric power. In 2019, the company scheduled to test this technique using the tailings from the beneficiation plants at the Letseng mine in Botswana.
Among the new developments in the primary beneficiation of the diamond-bearing ores, special mention should go to the Sepair dry (pneumatic) beneficiation plant developed by the Novosibirsk-based Gormashexport company. ALROSA tested the plant in 2011 using poor cut-off grade ores at the Sytykanskaya pipe in the Republic of Sakha (Yakutia). One of the main advantages of this technology is the possibility to work at extremely low temperatures (down to minus 50oC), which is especially important in the severe climate of Yakutia.
Module beneficiation plants are used to process primary deposit ores as well as placer ones, including the ores in detailed exploration. In Russia, these plants are manufactured by Technologies, Equipment and Integration, a research and development company based in St. Petersburg.
The module equipment consists of primary jaw crushers, scrubbers, dense medium separation plants and X-ray units. The units can be used separately or as part of the beneficiation plants. For example, a beneficiation plant OK-Komplekt-4 consisting of three module units: a unit for beneficiation of bulk kimberlite samples, for beneficiation of kern kimberlite, bulk and smallsize alluvial samples, and units for conditioning of concentrates, has a capacity of 4 tons per hour. The main advantages of the module beneficiation plants include: the possibility of transportation the equipment by usual freight vehicles; the possibility of installing them on the unequipped sites near mine workings, and low power consumption.
On the whole, the technology development level for the beneficiation of diamond-bearing ores in Russia and abroad is approximately the same. That said, the main driver of the technological progress in the ore processing and diamond extraction in the country is, undoubtedly, ALROSA, the leader of the national diamond mining industry.
beneficiation in the diamond industry - news from all diamond
When compared to other major industries like telecommunications, oil and gas, or consumer electronics, the diamond industry is relatively small. However, as I have noted in the past, the diamond industry employs an estimated ten million people around the world, both directly and indirectly. It also inspires dazzling artistic creations, and offers savvy investors a wealth preservation asset in times of financial turmoil. But some of the most important benefits that the diamond industry creates are often the least well known to the general public and the media.
Every diamond producing country is different in the way it chooses to capitalize on the diamond resources buried in the ground within its borders, but all attempt to leverage diamonds in some way or another to benefit society as a whole. In my next series of articles, I will look at what has become known as beneficiation, or the downstream benefits that can be achieved by mining diamonds.
The primary meaning of beneficiation in the mining industry is a process in extractive metallurgy that improves the economic value of mined ore by removing non-commercially valuable minerals. The diamond industry has used the term for many years in reference to other downstream activities, such as cutting and polishing, that create additional economic value to a producer country beyond just the value of the rough diamonds it produces. In recent years, the word has been adapted even further, and many now use the term more broadly to refer to the overall benefit achieved through diamond activities in a given nation. This broad definition of the word is what I hope to explore over the next few weeks.
Although the early goals of beneficiation in any country are usually fair and just, the long-term results do not always align with the hopes of its architects. Some countries have been utterly transformed by diamonds for the good, while the benefits to others have not been equitably distributed. Conversely, some countries that have never produced a single mined diamond have become epicenters for the industry. In some places, beneficiation has become a natural byproduct of the presence of diamonds nearby, while in others it has been forced upon the industry in ways that have proven unsustainable. As countries like Namibia and Zimbabwe continue to explore ways to gain more benefit from their diamond resources, the successes and failures of other nations are on display for those who will design future strategies.
The most common form of beneficiation is when a producer nation mandates that a certain proportion of its rough production must be sold to local manufacturers to produce polished diamonds. This ensures additional employment outside of the mining, sorting, and sale of rough stones, and also helps local businesses capture any additional profit margin from manufacturing. Local firms are able to create national marketing campaigns around both the diamonds and the finished jewelry that are mined and cut locally. A Nielson study has shown that 75% of consumers say that a brands country of origin is as important as or more important than other drivers such as price, function, and quality. It is no surprise that jewelry manufacturers in many diamond-producing countries have been somewhat successful in selling locally mined and cut diamonds.
However, the largest diamond consuming nations, such as the USA, India, China, Japan, and the Eurozone, produce virtually no diamonds of their own. In contrast, producer nations like Canada, Australia, Botswana, Russia, and South Africa are not amongst the major consumers of diamond jewelry. This means that efforts to cut and sell locally are limited by the internal demand for diamonds, and the majority of finished goods are destined for foreign markets. Perhaps more importantly, the skill of local workers and the development of new manufacturing technologies are an impediment for most producer nations, as countries like India and Israel have excelled in these areas.
Using a broad definition of the word beneficiation shows much additional benefit to a producing country beyond just the downstream cutting and polishing industries. Due to the topography where diamonds are most often found, major infrastructure developments are often needed to bring roads, electricity, and supplies to a diamond mine. This type of investment can, in some cases, be worth billions of dollars to local economies, and provide ongoing benefits long after a diamond mine is shuttered. In some countries, the presence of roads that were built to support diamond mining activities can continue to open up new opportunities in resource extraction and new settlements for decades to come. Electricity infrastructure is another profound benefit of diamond mining, as most diamond producing regions lack adequate power generation prior to it being delivered to support mining work. Countries like Canada and Lesotho provide examples where previously inhospitable areas are now thriving as a result of power infrastructure being distributed for diamond mining.
Further beneficiation from diamonds comes in the form of direct royalties to governments that can be used for the greater good of the economy. Virtually all companies mining diamonds must pay some form of royalty to various levels of government within the region and nation. This is a common feature of all types of mining activities. They range from as little as four percent to more than 20 percent. These royalty payments often become part of a governments general revenue, which is used as required based on the individual countrys finances. However, different nations have been more and less productive with their diamond income. Botswana, for example, has used diamond revenue to transform itself from one of the poorest nations in the world, to one of Africas richest and most productive countries. Other places, such as the Central African Republic, which has plentiful diamond resources, remains amongst the poorest and least developed areas in the world.
Over this next series of articles, I will look at the beneficiation efforts of many different countries to see how some have succeeded, while others have failed. I will try to carve out a roadmap for governments who are currently looking to establish or amend their own diamond beneficiation guidelines for the benefit of future generations.
The views expressed here are solely those of the author in his private capacity. No one should act upon any opinion or information in this website without consulting aprofessionalqualified adviser.
Diamond industrialist Ehud Arye Laniado is a man passionate about diamonds. From his early 20s in Africa and later in Belgium honing his expertise in forecasting the value of polished diamonds by examining rough diamonds by hand, till today four decades later, as chairman of his international diamond businesses spanning mining, exploration, rough and polished diamond valuation, trading, manufacturing, retail and consultancy services, Laniado has mastered both the miniscule details of evaluating and pricing individual rough diamonds and the entire structure of the diamond industry. Today, his global operations are at the forefront of the industry, recognised in diamond capitals from Mumbai to Tel Aviv and Hong Kong to New York.
Nothing on this website can be construed or constitutes an offer or a recommendation to sell or to purchase diamonds or the solicitation of an offer to purchase any diamonds nor does it constitute an offer or a recommendation to sell or to purchase any security or financial product or the solicitation of an offer to purchase any security or financial product. >> Continue to full disclaimer
diamond processing plant works towards dmrs local beneficiation outlook
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The money that is generated from local beneficiation can then be put to good use. [There would be] new skills transfer programmes and new jobs, and this would mean a new dawn for the country, she said last week at the official open- ing of the East London indus- trial development zone-based Matla diamond beneficiation plant, a joint venture between black economic-empowerment company Matla Innovation and Chinas Gold Eastern.
The R102-million investment will create capacity within the province to beneficiate smaller rough diamonds into polished product of 0,10 ct to 1 ct. Currently, South Africa has limited capability to benefi- ciate smaller diamonds, which represent more than 85% of all rough diamonds produced in the country.
Matla Innovations chairperson Zwelakhe Sisulu reported that construction of the plant started in September last year and was completed in March this year. Matla had already commissioned its machines and had brought in senior technicians from China.
The plant is modelled around similar state-of-the-art facilities in China and India. The Matla beneficiation plant is modelled around the companys technical partners plant in Panyu, China. The Chinese plant has a manufacturing capacity of 60 000 ct/m, said Sisulu.
He added that the East London facility was designed to have a maximum capacity of 20 000 ct/m. In addition, the plant had also procured an intelligent security monitoring system from the Industrial Technology Research Institute, in Taiwan. The system would provide safety and security for the manufacturing facility as well as the workers within the facility.
Matla Innovation CEO Chia-Chao Wu reported that the emergence of a large Asian and African middle class had created a significant new market of potential first-time diamond buyers, who would increase the global demand and value for diamond jewellery sets. South Africa could potentially benefit from this market if it processed and beneficiated smaller jewellery sets.
The successful development of a diamond processing plant in the Eastern Cape could potentially lead to further high-value job opportunities in both beneficiation and large-scale jewellery manufacturing in the province, said Wu.
A feature of the plant would be its skills development programme. Wu explained that experienced Chinese workers, who were familiar with the technology, currently operated the diamond plant, but that they had to transfer their knowledge of the technology to inhabitants of the Eastern Cape within two years.
Matla Innovation is tar- geting to train between 150 and 200 people a year as cutters and polishers. The plant will create up to 120 skilled-job opportunities in the Eastern Cape over the next two years, and more than 500 jobs over the next five years, said Wu.
He added that one of the main reasons that the Matla Innovation group deci- ded on the Eastern Cape as a location for the facility was that it had many qualified young people who were willing to learn but, more importantly, needed the specialised skills and the employment opportunities.
Sisulu reported that, with the automated nature of the plant, Matla would be spend- ing between $25/ct and $40/ct on these activities within the first year of operation. Looking beyond that, Sisulu reported that the Chinese benchmark of $17/ct was well within reach.
Edited by: Martin ZhuwakinyuCreamer Media Senior Deputy Editor EMAIL THIS ARTICLE SAVE THIS ARTICLE
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diamond mining equipment
The beneficiation methods for diamond primary ore and placer of diamond have own similarities and differences, but basically, they can be divided into two stages, i.e. roughing and concentration. Rough is achieved mainly by gravity separation with the jigging machine; while concentration is conducted by various methods jointly. Quality is important during the entire beneficiation process. The quality inspection should be taken in each step with various methods on the different quality requirements for each grade. The required total recovery rate for diamond is not less than 95%.Diamond is a rare and valuable mineral resource. Mineral processing is currently the only effective method for determining the diamond content in the ore. The purpose of diamond beneficiation is to dissociate and select the monomeric diamond from the ore and recover the gold-associated minerals as much as possible. JXSC diamond mining equipment assists you to bring greater profit.
The ore dressing is divided into two stages: rough and concentration.1.1 Rough selectionThe rough selection operation is mainly carried out by the jigging machine. The upper limit of the selected particle size is 16 mm, and the lower limit of the recovery particle size is 0.2 mm.(1) Primary ore: firstly crushing and grading (weathering samples need to be pre-screened), then jigging and sorting. The jigging tailings enter the grinding operation, then dissociate the undissociated diamonds. After dissociation Return to the jigging sorting cycle several times until the ore is ground to the lower limit of the selected particle size.In the samples with strong weathering, it usually contains more clay and has a strong bonding effect. Before the sorting, it is necessary to carry out washing and pre-screening before selection. ore crushing and desliming procedure to prevent loss and breakage of diamonds.(2) Sand ore: In the sand ore, the diamond particles are present in the form of monomer and loose sand or glued with clay. The coarse concentrate can be obtained after these processes: washing, sieving, grading and desliming, separating the large gravel and fine mud tailing, clean sand jigging separation.1.2 ConcentrationAccording to the nature of diamond and coarse concentrate, the concentration selection operation is carried out in a combination of various methods. Generally, >4mm by hand picking, -4+1mm by X-ray separation or oil separation, -1+0.2mm by particle floatation, shaker table, magnetic separation, gravity separation, selective grinding, alkali fusion, heavy liquid separation and microscopic selection. the tailings of concentrate sand ore are generally discarded.The tailings of primary ore concentration which bigger than 0.5mm need to be re-grinding, if <0.5mm, discard it.
(1) Diamond is mainly produced in kimberlite. The content of heavy minerals in kimberlite varies with kimberlite type and origin, but most of them (about 99%) have lower specific gravity than diamond. Therefore, a heavy selection method is one of the effective methods for diamond ore sorting.
(2) Jigging ore dressing is a gravity separation method that uses the difference in specific gravity between minerals. It does not need to add any chemicals, so there is no chemical pollution in the beneficiation process. The practice of many years shows that the effect of jigging and sorting is good. The process is simple, and the operation and management are convenient. Especially in the geological experiment stage, it shows the advantages of high recovery rate and light equipment, which is a method widely used at home and abroad.
(3) The basis of the diamond mining equipment selection is the physical and chemical properties of the mineral, such as color, gloss, hardness, specific gravity, shape, particle size, magnetic permeability, electrical conductivity, surface wettability, wear resistance, etc. The method is reliable and the effect is good. contact us to get the latest price of diamond mining equipment and diamond process flowsheet. JXSC is 30+ years of mining equipment suppliers in South Africa.
Mining Equipment Manufacturers, Our Main Products: Gold Trommel, Gold Wash Plant, Dense Media Separation System, CIP, CIL, Ball Mill, Trommel Scrubber, Shaker Table, Jig Concentrator, Spiral Separator, Slurry Pump, Trommel Screen.