Exploration on the process of recovering nickel metal from washing water in concentrator
Jilin Jien Nickel Industry Co., Ltd. is located in Hongqiling Town, Panshi City, Jilin Province. It is a medium-sized non-ferrous enterprise integrating mining, selection, smelting and chemical integration. After decades of development, mineral processing plant daily processing ore 1500t. The main metal ore sulfide pyrrhotite, pentlandite, and a small amount of brass ore pyrite. In addition, the ore also contains a large number of easily muddy secondary magnesium- rich silicate gangue minerals, such as talc , fibrinite, chlorite, serpentine and biotite, etc., gangue minerals generally contain 0.1% Nickel. The ore is mainly composed of orthorhombic pyroxenite and Suchangyan. Due to self-change and hydrothermal action, most of the minerals such as orthopyroxene become fibrillite through fibrillation, shale petrochemical, green mud, and petrochemical. ( Tremolite ) talc, chlorite and vermiculite, etc., strong alteration is a very rich mud-rich magnesium silicate mineral, while the main nickel-bearing mineral pentlandite and nickel-containing pyrrhotite It is fragile and easy to oxidize and is rich in iron sulfide minerals. Therefore, the original ore is a copper sulfide nickel ore that is easily muddy and oxidized during the grinding flotation process. Because the slime has the characteristics of small particle size, large specific surface area and unsaturated surface bond, it can cause three major consequences: The recovery rate of ore dressing is low, the quality of concentrate is poor, and the consumption of drugs is large. The main cause of the above-mentioned hazards is the formation of a slime cover on the surface of pentlandite and nickel-bearing pyrrhotite, which affects the adsorption of collectors by useful minerals and inhibits flotation. Calculated according to the 8% mud content, the daily production of ore washing mud is 120t, which is rich in a large amount of recoverable nickel minerals.
Since 1976, the mineral processing water recycling process of the concentrator has experienced poor performance after five technical changes. At the beginning of 2008, the production department of the company cooperated with the concentrator to test and design the washing water resource recovery process of spiral flow tank de-sludge-concentrate re-grinding flotation [1 ~ 3] . Since the test run in June 2008, it has been half a year. The technical indicators for washing water resources recovery are better, effectively solving the problem that has plagued the concentrator for many years.
I. Introduction to the original washing water recovery process before technical upgrading
The Hongqiling copper-nickel sulfide ore is high in pyrrhotite, the gangue mineral is easy to be muddy, and the primary slime content is large. The miner's section of the ore dressing plant adopts a three-stage and one-closed process. The ore is broken to -16mm and then enters the figure shown in Figure 1. For the process, the flotation process shown in Figure 1 is used for the sorting operation, and the flotation machine is a 6A flotation machine. Since the production operation, the following problems have been found: 1 Due to the nature of the ore, the amount of mud in the washing water is too large. 2 Due to the impact of the broken car between the miners, the concentration of the washing water slurry is extremely unstable, and the lowest in the site inspection was only 8% to 9%. 3 Due to the impact of the broken car between the miners, the amount of ore washing water is too small and unstable.
Figure 1 Raw washing water treatment process
Because the above three main factors have greatly affected the effect of the sorting operation, the technical indicators are extremely unstable after the washing water enters the flotation, and the metal recovery rate of the nickel concentrate is low. Table 1 shows the technical indicators of the washing water of each class obtained by random sampling before the transformation of the washing water.
Table 1 Status of washing water before transformation in 2007
It can be seen from Table 1 that the indicators of on-site washing water operation are extremely unstable and the indicators fluctuate frequently. Although the original ore grades are basically similar, the nickel metal recovery rate index is low, the metal loss is serious, and the flotation index fluctuates frequently, and there is no obvious law.
2. Process status of washing water recovery after technical upgrading
In view of the serious metal loss on site and frequent fluctuations of product indexes, after the relevant test demonstration of the mineral processing laboratory, the process flow as shown in Figure 2 was initially determined. The washing water slurry was transferred into 9 BL-1500B spiral chutes (developed by Beijing Research Institute of Mining and Metallurgy) through φ2l9mm pipeline self-flow mode for a period of dewatering and dewatering. One section of concentrate was entered into 3 BL-1500B spiral chutes for two stages. The final concentrate after dewatering and dewatering is transported by sand pump to a separate storage silo for the purpose of storing enough pulp to provide raw materials for continuous and stable production of flotation operations when the mine is parked. The concentrate is drained. After entering the ball mill and grinding, and then enter the separate flotation system, and the flotation tailings together with the re-election mud into the 1 # tailings pumping station. Since the trial operation, the washing and water resources recovery process has been working. The process is simple and easy to operate, and effectively avoids the problems of large amount of mud washing water, low concentration and intermittent driving of the crushing workshop.
Figure 2 Process of washing water treatment after transformation
(1) Index of washing water resources after reformation
After the technical transformation, the washing water treatment process consists of two parts, the re-election operation by spiral chute and the flotation operation by GF series flotation machine. Therefore, the technical indicators of the washing water resource recovery process should be composed of these two parts. .
1. Spiral chute de-sludge dewatering process index
Because the washing water comes from the slime washed by the crushing workshop, the pulp volume is affected by the washing water pressure, the ore mud content and the ore particle size, resulting in uneven flow of the washing water slurry, intermittent and intermittent sampling. The sample and the actual situation are more serious. The indicators of the dewatering and dewatering concentrate of the spiral chute are shown in Table 2, and the time refers to June 2008. Among them, the negative recovery rate of the three shifts of nickel on June 4 and the recovery rate of the second shift of nickel on June 11 are more than 100%, which are unreasonable, so they are not representative and may not be used.
Table 2 Detachment and Dewatering Index of Spiral Chute after Technical Reform
According to the actual measurement, the recovery rate of nickel metal in the actual yield of the dewatering and dewatering process of the spiral chute is about 60% to 70%.
2. Washing water re-grinding flotation process index After the degreasing and dewatering washing water slurry is re-grinded, the fresh surface is ground on the ore surface and effectively avoids the problem of large particle ore difficult to be selected due to storage. The mine storage and mineralization makes its independent operation independent of the crushing mine workshop, which makes the selection index better. The indicators are shown in Table 3.
Table 3 Index of washing water flotation after the technical reform in June 2008
3. After the transformation of the comprehensive index of the washing water resources recovery process
The recovery rate of the dewatering and dewatering process of the spiral washing tank is 70%, and the average recovery rate of the re-grinding flotation process is 75%. The comprehensive recovery rate of the washing water after the transformation is 52.5%.
(2) Problems after the technical reform
Through investigation, it was found that during the actual trial operation, the comprehensive recovery rate of nickel metal in washing water was only 52.5%, which was far lower than the technical recovery index (80%) obtained by the test. After investigation, it was found that there are mainly the following problems: 1 Washing water contains many fine mineral muds. An important reason why fine slime is difficult to re-separate is that the surface force is enhanced and the effect of poor mineral density is weakened. Studies have shown that the dynamic potential of the surface of the ore particles has an important influence on the sedimentation stratification of the particles. This natural property is utilized to change the properties of the surface of the particle by means of the agent, or to selectively agglomerate it for reselection separation. This is a research direction. Due to the limitations of the site conditions, it will not be considered for the time being, and will be considered when the conditions are ripe. 2 Because the desilting and dewatering process of the spiral chute is affected by the water pressure of the washing water in the crushing workshop, the mud content of the ore and the ore grain size, the amount of washing water slurry is unstable, intermittent, and the sorting effect is not ideal, and even a large number of purposes Minerals are lost as they enter the tailings. 3 After re-concentration of concentrate and de-grinding, it still contains a certain amount of washing ore, and the size distribution of the concentrate is uneven. The content of -0.074mm is only 40% to 50%, and the target mineral nickel is dissociated. The degree is far from meeting the flotation requirements, resulting in a nickel metal recovery rate of only 75% in the washing water flotation stage.
(3) Improvement measures
Based on several problems in the operation of the above washing water treatment process, consider the following measures:
1. Screening each product of the washing water, and found that the yield and recovery rate of the spiral chute coarse concentrate product and the concentrate product are similar, and the indicators are shown in Table 4.
Table 4 Size distribution of spiral chute concentrate and coarse concentrate
It can be seen from Table 4 that the yield and recovery rate of the spiral chute coarse concentrate product and the concentrate product are similar. Therefore, it is recommended to incorporate three BL-1500B spiral chutes in the second section of the spiral chute dewatering and dewatering process into a roughing operation to improve the instability of the washing water slurry flow. The selection process of the desilting and dewatering process of the spiral chute was cancelled, and three BL-1500B spiral chutes were selected for rough selection.
2. Through on-site inspection, it was found that the re-elected concentrate was de-sludged and re-grinded, and the -0.074mm fraction only accounted for 40% to 50%. Therefore, it is considered to carry out the second section of the grinding test. The test samples were taken from the overflow of MQY1200×2400 ball mill. The comparison of unground and reground flotation is shown in Table 5.
Table 5 Comparison of unground and refurbished flotation of deslimed dehydrated concentrate
It can be seen from Table 5 that after re-election of concentrates and re-floating and flotation, various technical indicators have been greatly improved, and satisfactory results have been obtained.é‚ Consider the grinding of the concentrate after dewatering and dewatering through the spiral chute, and then introduce it into the 2FG-24 spiral classifier of the large system No. 3 ball mill to realize large particles entering the large system and grinding the grinding machine. As the large system slurry enters the next operation, it enters the large system flotation. Due to the small amount of concentrate ore after dewatering and dewatering of the washing water, the buffering effect of the large system is used to effectively recover this part of the nickel resources, and the tailings grade fluctuates within the normal range without negatively affecting the large system. At the same time, the tailings abandoned after the original dewatering and dewatering were changed to the current washing water GF flotation machine to recover the nickel minerals lost in the tailings as much as possible.
(4) Technical indicators after the process is improved again
After the process improvement, the original GF-type washing water flotation machine was changed to the mud-containing tailings after the dewatering and dewatering of the washing water. The flotation indexes are shown in Table 6.
Table 6 Flotation index of mud tailings after the process is improved again
Since the concentrate after desilting and dewatering in the spiral chute has not been adversely affected by the large system index after the incorporation into the large system, the recovery rate of the selected washing water resource in the large system is 80%, and the desilting dewatering process of the spiral chute is cancelled. The recovery rate of selected operations was slightly improved, the recovery rate was 70% to 75%, and the recovery rate of mud tailings flotation was 29.8%. The comprehensive recovery rate after process improvement was 64.94%, which was still tested with the laboratory. There is a certain gap in the results. I believe that as time goes by, the technical indicators will improve after the production is gradually normal.
(5) Comparison before and after improvement
See Table 7 for comparison of technical indicators for washing water resources before and after renovation. The annual average processing capacity of the Jean Nickel concentrator is 360,000 tons. The daily production of ore washing water accounts for 8% of the daily processing capacity, the original ore nickel grade is 1%, and the nickel price is 16 tons per ton of electrolytic nickel in July 2008. For ten thousand yuan, the nickel metal of the concentrator is denominated as 60% of electrolytic nickel. It can be seen from Table 7 that the technical indicators after the improvement of the washing water technology are obviously improved, and the benefits are remarkable.
Table 7 Comparison of washing water resources indicators before and after renovation
The nickel price is calculated based on the 160,000 yuan per ton of electrolytic nickel in July 2008. The nickel metal of the concentrator is calculated as 60% of the electrolytic nickel. It can be seen from Table 7 that the technical indicators after the improvement of the washing water technology are obviously improved, and the benefits are remarkable.
Third, the conclusion
1. Compared with the nickel concentrate grade of 3%~4% of the washing water before the transformation and the nickel metal recovery rate of about 45%, after the process of washing the water, the 5% to 7% of the main process is obtained. Nickel concentrate grade, 64.94% nickel metal recovery. After the conversion of comparable raw ore, the comprehensive recovery rate of nickel metal can be increased by nearly 0.5%, and the effect is remarkable.
2. The use of spiral chute de-sludge. The refinery re-floating flotation washing water resource recovery process has a new way to technically reform the washing water resources recovery process of Jean Nickel Co., Ltd., avoiding the drawbacks of the previous technical transformation process. . The recovery rate of nickel metal for washing water resources has been significantly improved, effectively solving the problem of metal loss of mineral resources in the past years, with remarkable effects, which can significantly improve the utilization rate of the company's resources and improve economic efficiency.
3. The trial operation results show that the technical transformation is scientific, reasonable and feasible, and can achieve better recovery results of slime resources.
4. The process of recovery of washing water resources still has the problem of low recovery rate of nickel metal in fine slime. It is necessary to consider corresponding measures in the future (such as considering the use of chemicals that have no effect on the next stage of flotation. Modification, to improve re-election technical indicators; extend flotation time, etc.) to solve.
references
[1] Sun Yubo. Gravity beneficiation [M]. Beijing: Metallurgical Industry Press, 1991.
[2] Xie Guangyuan. Mineral Processing [M]. Xuzhou: China University of Mining and Technology Press, 2001.
[3] Wang Dianzuo, Qiu Guanzhou, Hu Yuehua. Resource Processing [M]. Beijing: Science Press, 2005.
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