See also: detailed description in Russian magazine "Dobycha Zolota"(Gold Mining) - Volumes 116, 117, 118 (July, Aug. Sept. 2008) - Complete set of 3 articles (PDF, in Russian) and On-line translation by GOOGLE to English
1. Description of the project.
2. Brief description of scientific and technological products.
3. Analysis of the market.
4. Manufacturers of competitive products.
5. The price of products.
Valery Pugachev, Inventor
1. Description of the project.
The task of Ltd. «Pugachev and Partners» is the research and development activities to create the first industrial models of centrifugal-type inertia concentrators PCC-2 (capacity of up to 0.2 tons/hour of solid ores) and the PCC-3 (capacity of up to 3 tons/hour of solid ores), to extract the small (less than 0.25 mm) and thin (less than 0.1 mm) grades of precious metals (gold, platinum and silver) with a gravitational method of enriching the mineral and industrial control system.
2. Brief description of scientific and technical products.
We know that the centrifugal method of enrichment is a progressive and most effective for gravitational enrichment of fine blends (placers or regrind ores), containing small and thin grades of heavy minerals. This method has been widely distributed in the global gold mining, when during the development of sand placers and regrind ores containing precious metals, in the schemes enriching centrifugal concentrators used different designs, with different way of a bundle of pulp material and a concentrate.
The best-known and common centrifugal concentrators are produced by Canadian firms «KNELSON» and «FALCON», the American company «GOLDFIELD» and Russian firm «ITOMAK».
Despite the high technical and economic indicators (high productivity per 1 m² production area, a high degree of reduction of concentrate, environmental cleanliness of the process of enrichment possibility of extracting small classes of precious metals) data centrifugal concentrators did not find widespread use in artisanal gold mining in the region, away from sources of clean water, especially on the African continent.
Using the returned (used) water for these concentrators (with the exception of gold concentrators by Ltd. «Pugachev and Partners») requires thorough cleaning for her «liquefaction» mineral bed, formed in the enrichment process in the flute rotating bowl, and the existing filters fail. Moreover, these concentrators are very high priced, having low extraction of fine gold, especially flaky and plate shape (no more than 30%), they are unstable at placer (alluvial deposits) with a high content of clay fractions, they require highly skilled service personnel because of the complexity of construction machines.
Centrifugal-vibration concentrators by Russian company Ltd. «Pugachev and Partners» have the best rates to recover small and fine gold, they have adapted to the conditions of artisanal gold mining.
The goal of our work was the creation of centrifugal inertial-concentrator model PCC-3 (the diameter of the bowl 250 mm), designed for high-quality gravitational enrichment at the industrial small production and processing of ore and loose deposits and industrial dumps of past workings, containing small and fine-grained gold, platinum, silver and other heavy valuable minerals, including Mercury.
Concentrator PCC-3 can also be used for industrial processing of non-traditional (technological) raw materials containing precious metals:
- Processing of sand and gravel mixtures;
- Processing of non-metallic piles and fixed ash from heat-electric generating plants;
- Processing of metallurgical slag production;
- Processing of electronic scrap.
Concentrator developed on the basis of new technical solutions (know-how) to implement a new way of segregational separation of mixtures and a device for its implementation.
The new way of enriching the pulp with a predominance of small and thin fraction of precious metals will be the principle of segregation (heavy infiltration of small particles through the gaps between the grains of large light particles), based on the centrifugal forces of high-frequency regulated vibrations, intensifying the process of bundles of mineral bed on specific weight.
On the effectiveness of the enrichment process and the original design, the PCC-3 has no analogues in the world's engineering and favorably distinguish itself from the best concentrators of the same size (10”):
- More productive;
- Higher extraction of small and fine-grained gold;
- Smaller size and weight;
- Ease of maintenance;
- Adaptable to the conditions of artisanal gold mining;
- Controlled regime of enrichment according to the mineral composition of raw materials;
- Speed unloading of depleted concentrate.
All this, coupled with affordable price (compared to the best Canadian model KS - CD10 «KNELSON» of the same class) will pave the way for widespread introduction of a new concentrator PCC-3 to all gold-mining regions of the world, including in Africa.
3. Analysis of the market.
World gold mining has been going for many centuries. During the long period, the production areas have accumulated an enormous amount of man-piles, which are currently due to the depletion of mineral resources are considered as a potential source of replenishment of raw materials base.
Of particular significance here is the tail enrichment, as the imperfection of technology and equipment, the violation of technological regulation (lack of completion - grinding ore, poor quality washing of sand, placers, unregulated regime of pumping water, bad reverse water purification, losses in the removal of concentrate and its further refinement) technological loss of precious metals from tailings processing reaches in the ore heaps up to 30%, and in the placer deposits - up to 50% of the original content.
Numerous studies by scholars and professionals of several countries, conducted in 90s of the last century, found that the major loss of valuable components are in the small (less than 0.25 mm) and thin (less than 0.1 mm) size classes. This is particularly true for mining ventures and prospectors’ crews, who are in the business of mining precious metals (gold, silver, and platinum), Polymetal (tin, copper, zinc, tungsten, titanium, and zirconium) and iron.
That is why during the last two decades designers-enrich men around the world are working towards the creation of high-technology equipment for the extraction of small and thin grades of heavy minerals in environmentally friendly ways, since tailings pond of most major big ore mining and dressing plants usually located within 1 - 3 km away.
Analyzing the best industrial centrifugal concentrators in the world – made by Canadian firms «KNELSON» and «FALCON», the Russian company «ITOMAK» shows that the maximum extraction of small and fine-grained gold at these vessels, with an average productivity of 7 - 9 tons per hour on the hard ore does not exceed 50%, and in real-life environment - no more than 40%.
Since the concentrators mentioned above, because of the scarcity of clean water can not be operated in many countries in Africa, for processing only 1 million tons of old enrichment tailings during 1 year would require to produce about 300 pieces of centrifugal concentrators PCC-3. Taking into account the needs of other regions in gold mining world where gold extraction is permitted, the total market for the new concentrator will be approximately 500 pieces per year.
4. Manufacturers of competitive products.
From the well-known companies that have reached the best results in the creation of industrial centrifugal concentrators to improve the extraction of small and thin grades of precious metals in comparison with other technical means of gravitational enrichment, are:
1. KNELSON CONCENTRATORS, INC (Canada)
2. FALCON CONCENTRATORS, INC (Canada)
3. GOLDFIELD ENGINEERING (USA)
4. Scientific-Production Company ITOMAK (Russia)
Production of the firms (Centrifugal concentrators) is available in over 10 years and is well known to consumers. As the practice of exploiting, these concentrators have common weaknesses - a low degree of extraction of small and, in particular, the fine class size of gold. Virtually no one type of vessel does not reach the passport characteristics to derive at an average productivity. In addition, these devices because of its structural analogy to bundle mineral bed flute bowls require special training «liquidizing» water (thorough cleaning of mechanical impurities), which leads to significant capital costs, even with small amount of raw gold.
An analysis of the scientific, patent and special technical information shows a lack of technical solutions that could compete with centrifuge - inertia concentrator PCC-3 as on productivity, and to remove small and fine size classes of heavy metals. The transition of these firms to produce under license (using KNOW-HOW by the authors of the centrifugal method - inertial separation of mixtures and a device for its implementation) requires a large investment and overcome the psychological and market barriers. In response to these factors, the nomenclature and strategies release of gold concentrators at these firms is not expected to change very soon.
5. The price of products.
Since creating the centrifugal - inertial concentrator PCC-3 refers to products of production for technical designation (for the extraction of precious metals), the price depends on creating economic benefits.
To calculate take specific object - tailings dump left after processing of gold-quartz veins on the Londoni (Tanzania). Proof analysis of numerous samples indicated that the content of gold in the tails ranged from 9 to 25 g/ton. Phase analysis revealed that 40% of the total gold content is free, while some 45% - in crystal-jam with the quartz. Given the fact that some of the bounded gold is going to be ejected in the gravity concentrate (15%), level of recoverable gold will be at least 8 g/ton.
Mineralogical studies of tails revealed that the value of gold particles varies widely: from 0,5 - 1,0 mm of plate - uneven shape (5%) to 0,1 - 0,25 (approximately 70%) and further to 10 - 20 microns (25%).
Thus, the raw material belong to the difficult concentrability, since virtually all gravitated gold is in a small, fine and disperse class size.
Economic effect is determined in comparison with the best world analogue - centrifugal concentrator by Canadian company «KNELSON», model KS - CD10 with central discharge.
This concentrator has maximum capacity of 1.81 tonnes/hour for the file-hard, while the extraction of gold at grade - 0.25 mm does not exceed 50% (Records of mining companies using concentrators «KNELSON».).
The exploited concentrator PCC-3 will have a maximum capacity of 3 tonnes/hour for the file-hard. To ensure the extraction of small and fine-grained gold at 80% capacity, the capacity of PCC-3 should be reduced to 2 tones/hour.
Reprocess 1 ton of tailings site Londoni (Tanzania):
- Concentrator «KNELSON» COP - CD10 extract the gold concentrate at 8 * 0.5 = 4 g Au
- Concentrator PCC-3 extract the gold concentrate at 8 * 0.8 = 6.4 g Au.
Thus, from 1 ton of old tails, extraction of gold by PCC-250 is more at 2.4 g.
During 1 hour of work of concentrator PCC-3, the difference in extra extracted gold is 2 * 2.4 * 0.9 = 4.32 g Au
where: 2 - rated the performance PCC-3 with raw materials containing small and fine-grained gold;
0,9 - load factor PCC-250 on time, taking into account its inactive time during unloading the concentrate.
During the day (with single mode) further extraction of gold in a new centrifugal concentrator PCC-3, compared with the best world analogue KS - CD10 is 4.32 * 8 * 0.85 = 29.37 gram of Au
A month (23 days) - 29.37 * 23 = 675 g. Au
Accepted term payback for the purchase, installation and operation of a new centrifuge - inertial concentrator PCC-3 equal to 2 months. During this period, additionally (compared to the concentrator «KNELSON» COP - CD10) by concentrator PCC-250 will be extracted 675 * 2 = 1, 350 gram Au (1,35 kg).
Given the high gold fineness of gold deposit «Londoni» (Tanzania) 760 – 880, additional cost of the recovered gold will be:
30,000 * 0.82 * 1.35 = $33,210.
Where: 30,000 - the price of 1 kg of gold to 01 May 2008;
0.82 - factor of gold fineness of mined gold (760+880) / 2 = 820.
The cost of installation and maintenance of concentrator PCC-3 for the period of mining (2 months) is approximately 25% of the value of received gold (about $8,300).
Revenue from the use of the PCC-3 of $33,210 - $8,300 = $24,910.
Thus, when the duration of payback is 2 months, sale price of concentrator PCC-250 may be approximately U.S. $25,000.
According to the company KNELSON CONCENTRATORS, INC, selling price of concentrator model KS - CD10 (without spare parts) amounts to U.S. $27,500.
At the initial phase of production we will schedule the sales price of concentrator PCC-3 below the price of Canadian analogue (taking into account the real purchasing power of African gold-workers) by 40% ie $27,500 - $27,500 * 0.4 = $16,500.
The cost of construction of a concentrator PCC-3 will not exceed U.S. $8,500 (expert assessment of the authors-developers of the PCC-3).
Thus, the profits from the manufacture and implementation of one peace of new product - centrifugal - inertial concentrator PCC-3 will be:
$16,500 - $8,500 = $8,000.
That is a good incentive for their production.