Huang Kaiguo

Jinchuan's huge reserves of nickel, 82% of the country's total reserves of nickel metal, ranking second in the world after Canada. In addition to nickel (Ni) metal, Jinchuan is also rich in copper (Cu), cobalt (Co), gold (Au), silver (Ag), platinum (Pt), palladium (Pd), antimony (Os), antimony (Ir ), 钌 (Ru), 铑 (Rh), etc., have industrial value for development and utilization. Relying on the unique advantages of resources and relying on scientific and technological progress, according to the national development plan, Jinchuan has developed from a wilderness on the edge of the Gobi Desert to a new industrial city. The motherland “takes away the nickel capital”, with an annual output of 40,000 tons of electrolytic nickel. One of the three major resource utilization bases in China.

However, Jinchuan's rich resources are still far from being fully exploited and utilized. From the perspective of sustainable development, there are still many problems to be solved. The following are just a few points on the mineral processing technology issues.

I. Development and utilization of nickel-poor mineral resources

According to the industrial grade of the Jinchuan ore body, the Ni-containing 0.3-0.99% is a poor ore, and the Ni≥1% is rich ore. So far it has been "taking rich and staying poor." However, more than one million tons of nickel metal is hidden in the lean ore, covering the top of the rich ore body. In order to develop production and reduce mining costs, it is imperative to develop and utilize lean ore. The lean ore nature is different from that of rich ore. The ore-poor ore Ni (0.65%) and Cu (0.35%) grades are less than half of the rich ore (Ni 1.6%, Cu 0.83%), and the lean ore Mg0 content (28%) is richer than the rich ore ( 22%) high. In order to obtain the same quality standard of nickel concentrate, the use of rich ore dressing technology to deal with poor ore can not get good results, we must study the new technology of nickel-poor treatment. In the “Ninth Five-Year Plan” for poor ore dressing research, the concentrate index obtained by our test is 6.70% of Ni grade (required ≥6.5%), 3.59% of Cu (no requirement), 5.24% of MgO (required 6.0-8.0%), recycling The rate of Ni is 75.42% (requires 75.0%), Cu is 77.51% (required) 65.0), which is characterized by: the MgO content in the nickel concentrate is significantly reduced, the Cu recovery rate is high, the process flow and the prescription are simple, and the drug consumption is low. If the problem of poor ore beneficiation in Jinchuan can be solved, the available nickel resources will be expanded by a quarter.

Second, improve the quality of nickel concentrate, reduce its Mg0 content and the comprehensive utilization of serpentine

Now it is required that the nickel concentrate of the beneficiation product contains Ni>6.0%, Mg0<6.5%, and the nickel concentrate which does not meet the quality requirement (Ni<6.0%, MgO>7.0%) still enters the electric furnace to produce high-ice nickel, but the electric furnace can High consumption, high production costs, and backward technology. It has been put into production for many years and is the first technology in Jinchuan flash furnace to produce high-ice nickel. It has advanced equipment, large production capacity, low energy consumption and low production cost, which will completely replace electric furnace smelting. However, the flash furnace has strict requirements on the quality of the imported nickel concentrate (Ni>6.5, Mg0<6.5%). If Mg0 is high, not only the recovery rate of Ni obtained by smelting is low, but the cost increases, and the slag viscosity is large, resulting in nodules in the furnace, corrosion of the furnace body, and leakage of the furnace. This is the harmful side of Mg0 entering the nickel concentrate for smelting.

On the other hand, the sorting out of the serpentine _{(3Mg0 · 2SiO 2 · 2H 2} 0) if the development and utilization, can be used for the production of calcium magnesium phosphate fertilizer (while recovering Ni therein), the production of the magnesium compound (including the light MgO, MgCO ₃ , feed MgS0 ₄ ·nH ₂ O), produces high-grade active SiO ₂ , water glass, glass raw materials, and comprehensively recovers Ni, Co, and the like. The MgO content in Jinchuan's ore is more than 20 times that of Ni, and serpentine accounts for more than 65% of the ore produced. It is a huge resource that can be comprehensively utilized.

As for improving the quality of nickel concentrate and reducing its MgO content, it is possible to reduce the MgO content in nickel concentrate to less than 6% from our results of the above-mentioned lean ore test. It is also possible to increase the grade of nickel concentrate at the same time. We have achieved good results in the “Seventh Five-Year” research: when the ore contains Ni as 1.71%, the raw ore is only finely ground, once rough selected, and once selected. With the unique process and prescription, the Ni grade can be obtained. 10.20% nickel concentrate with a recovery rate of 83.1%.

Third, improve the problem of copper recovery rate

The ore produced by Jinchuan currently contains about 0.8% of Cu, but the copper grade in copper-nickel concentrate is 3.0%, and the recovery rate is only about 75%, which is much lower than the domestic copper beneficiation index. One of the reasons is that heavy nickel light copper, There is no research on improving copper recovery rate, no special measures, no indicator requirements. From our experimental study on lean ore, it is shown that when the ore contains 0.35% Cu, a copper-nickel concentrate with a copper grade of 3.59% and a copper recovery of 77.51% can be obtained, and the copper recovery rate is higher than the nickel recovery rate (75.42%). In the test of mixed ore, the recovery of copper was 79.02%. It can be seen that it is possible to increase the copper recovery rate. If the recovery of copper and nickel is similar, the copper production will increase by 15%.

Fourth, improve the recovery rate of platinum group elements

Jinchuan nickel ore is rich in platinum group elements, mostly in mineral state, and contains (g/t) in ultrabasic rock-type nickel-rich ore: Pt 0.53, Pd 0.24, 0s 0.024, Ir 0.022, Ru 0.020, Rh 0.010, Au 0.30 and Ag 5.5. There is a large Pt rich ore section with a length of 98m and a width of 1~6.4m. The average Pt content is 6.15g/t and the highest is 81.67g/t. The average Pd is 1.83g/t and the highest is 11.8g/t. It has been estimated that the value of the platinum group element accounts for about 35% of the value of the entire ore. However, the recovery rate of platinum group elements is currently very low, see 50-60% or lower (29.91%), 70-80% or higher. It seems that Jinchuan has not yet had a special study to improve the recovery rate of platinum group elements. The technical measures for non-targeted selection and no assessment requirements are completely arbitrary and natural.

According to reports, in the international market, in addition to the rise in nickel prices, platinum (Pt) metals will be in short supply. This year, the global demand for platinum will be the highest in history. In the next five years, demand will remain strong and platinum prices will be firm. Palladium (Pd) is a valuable material for the treatment of automobile exhaust pollution. The international palladium metal prices continue to rise, and the New York market continues to break the record of the highest price in history, and will continue to strengthen in the future. Therefore, it is necessary to attach great importance to the study of improving the selection of platinum group elements.

In short, Jinchuan's sustainable development needs to include continuous innovation in mineral processing technology.

references

1 Jinchuan Nickel and Cobalt Research Institute, Emei, Zhengzhou Institute of Minerals Comprehensive Utilization. The relationship between Jinchuan craft minerals and crafts, 1987.

2 Huang Kaiguo, Chen Wanxiong, Peng Xianquan, Zeng Xiaoxi. A flotation process for low grade nickel ore. Chinese Journal of Nonferrous Metals, September 1999, Vol. 9, No. 3.

3 Reports and abstracts, platinum metal will be in short supply. International palladium prices continue. Rising, foreign metal ore dressing, No. 2, 2000, 46.

This article is written in the essay of 'sustainable development' and was selected into the book "China's Population, Resources, Environment and Sustainable Development Strategy Research" and won the "Excellent Paper Certificate", No. 01366.

Originally published as "Foreign Metal Ore Dressing" 2001. No.1. P.31-32 ☺

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