Xia Qing
CLC number: TD925.9 Document code: A
Jiangxi Copper Industry Company silver lead zinc mine Hill is a multi-metal mines. Due to the decreasing of lead and zinc resources, it has gradually transitioned to copper mines. Currently, it is about 1000 tons of copper-sulfur ore. The original copper selection process was a coarse-grinding mixed flotation, mixed concentrate re-grinding and re-election process. The process of copper and sulfur sorting is difficult and the ore dressing index is not high. Through in-depth analysis of the nature of the ore and the production process, after the year-end maintenance in 1999, the copper-sulfur mixed concentrate and copper-sulfur separation operation were used to select the tailings and enter the new process of re-grinding. After applying the new technology, the regrind strength was strengthened, the effect of copper and sulfur sorting was improved, and the beneficiation index was significantly improved.
1. Raw ore properties
The ore processed by the Yinshan Lead-Zinc Mine Copper-Sulfur System is a mixed ore of the Nine District Copper-Gold Ore, the Yinshan West District Copper-Silver Ore and the Copper-Containing Copper-Pb-Zn Ore.
1.1 Jiuqu Copper ore
The Jiuqu Copper-Gold Mine is a continental volcanic rock type medium-low temperature hydrothermal deposit. The ore contains copper, gold, silver, sulfur and other minerals, and is a copper-sulfur ore associated with gold and silver.
The main useful minerals chalcopyrite, tennantite, enargite, tetrahedrite, pyrite and the like. Gangue minerals are quartz and sericite. The ore containing arsenic mainly constitutes secondary copper sulfide minerals such as arsenic bismuth copper ore and sulphur arsenic copper ore.
Chalcopyrite is the most important copper mineral in the ore. It is produced in the form of irregular grains, veins, veins and spots. It is closely related to the incorporation of arsenic, copper and pyrite. The relationship between the gangue is simple. The arsenic-containing copper minerals are mainly arsenic bismuth copper ore and arsenic arsenide, followed by mixed bismuth copper ore, which is a secondary copper sulphide mineral. Its floatation is similar to that of chalcopyrite, but it is easily inhibited in high alkalinity. It is closely related to the inlay of chalcopyrite, and it is difficult for both to dissociate fully. The content of sulphur, arsenic and copper ore is less than that of arsenic bismuth copper ore. The distribution is less than that of arsenic and bismuth copper ore. The inlaid relationship with chalcopyrite is not as close as that of arsenic bismuth ore. It is more concentrated than irregular granules. Thick, closely related to the embedding of gangue and pyrite. Pyrite is the most sulfide mineral in the ore, and can be divided into early and late phases. Early pyrite crystals were better, and they were not closely related to copper, gold and silver minerals. The late pyrite is vein-like, strip-like, plaque-like, etc., often filled with chalcopyrite, arsenic bismuth ore, sphalerite, and some pyrite is irregularly granular, crumbly, and round in yellow. Copper ore and arsenic bismuth copper ore are inclusions. In the fragmented pyrite, the common chalcopyrite and arsenic bismuth ore are packed in fine veins and veins in the fissures. This part of the copper mineral particles is small and difficult to dissociate sufficiently. Analysis shows that pure pyrite contains 0.16% copper.
The comprehensive copper mineral contains 28.76g/t of gold, accounting for 57.06% of the original ore gold distribution rate, containing 467.8g/t of silver, accounting for 63.89% of the original ore. Pure pyrite contains 1.51g/t of gold, accounting for 42.83% of gold distribution, 17.2g/t of silver, accounting for 33.56% of silver. Analysis shows that gold and silver recycling is difficult.
1.2 Yinshan West District Copper and Gold Sulfur Ore
The copper-gold-sulfur mine in the western part of Yinshan is a polymetallic ore with associated gold and silver. The ore contains copper, gold and silver, and is also associated with tungsten, arsenic and sulfur. It has a high comprehensive utilization value.
The main copper minerals are chalcopyrite and arsenic bismuth ore; the main gold minerals are silver-gold ore and natural gold; the main silver minerals are natural silver, sulphur-copper-silver ore; the main gangue minerals are quartz and strontium. Mica, etc.; harmful elemental arsenic is mainly in arsenic bismuth copper ore and a small amount of arsenopyrite.
Chalcopyrite and arsenic bismuth ore are the main copper minerals in the ore. Not only do they have a very close relationship, but they are also closely related to the intercalation of antimony minerals and pyrite. At the same time, it is the main carrier mineral of gold and silver minerals, especially the arsenic bismuth copper ore is the product of the replacement of chalcopyrite and arsenopyrite. It is closely related to the intercalation of pyrite and is quite complicated. It is difficult to completely complete in the grinding process. Dissociation. Therefore, copper, gold, silver and arsenic in copper concentrates have a tendency to increase simultaneously.
Gold and silver mineral particles are fine, up to 0.05mm, generally less than 0.01mm. Chalcopyrite and arsenic bismuth copper ore are the main carrier minerals of gold and silver, containing gold up to 32g/t, accounting for 52.87% of gold. However, pyrite is the gold-silver carrier mineral second only to copper minerals, containing 3.2g/t of gold, accounting for 42.55% of gold, which is not conducive to the recovery of gold and silver.
1.3 copper lead zinc ore
The main minerals are chalcopyrite, galena, sphalerite, pyrite, containing a small amount of arsenic bismuth copper ore, ferrous iron, pyrite, arsenopyrite, brittle bismuth lead ore, copper blue and so on. Gold minerals include silver gold, natural gold, gold and silver, and silver minerals include deep red silver, silver and copper, and natural silver. The gangue is mainly quartz and sericite.
The mineral symbiosis combination is more complicated, and the ore structure mainly has breccia, strip, vein, disseminated and fine vein structure. The main minerals such as galena, sphalerite, chalcopyrite and pyrite are closely symbiotic, and most of them are medium-thick, medium-fine and fine-grained. Gold and silver are mainly distributed in the fine-grained structure of metal sulfide minerals such as lead, zinc and chalcopyrite. Some low-iron sphalerite and sphalerite are separated from chalcopyrite by solid-solution separation structure, and the relationship between copper and zinc is extremely close.
It can be seen from the above that the chalcopyrite and the arsenic bismuth copper ore, the chalcopyrite, the arsenic bismuth copper ore and the pyrite are very closely intertwined in the copper ore treated by the mine, and it is difficult to fully dissociate, and they are both Gold and silver carrier minerals, but their relationship with gangue is simple.
2. Production status before process improvement
The production process before the process improvement is one of the grid type and overflow type ball mills for rough grinding. The specifications are Ф2700mm×2100mm, and the grinding grade overflow fineness requirement is -74μm greater than 55%. Copper-sulfur mixed flotation primary rough selection, two sweeping selection process, using KYE, XCF8m 3 flotation machine combined unit, each operation is 3 slots, a total of 9 slots. The medium mine is re-grinded into a Ф1500mm×3000mm overflow ball mill with a Ф250mm hydrocyclone for pre-inspection and grading. The middle mine pump pool is a Ф6m thick pool. The regrind requirement is -74 μm 95%, -50 μm 85%. The copper-sulfur separation operation is one rough selection, three selections, and two sweeps. The JJF-4m 3 flotation machine is used, and each tank is 3 slots in the coarse and fine selection areas, and 6 slots in the sweeping area, for a total of 12 tanks.
The flotation reagent is a batch of flotation copper and sulfur mixed at the natural pH value, using xanthate (B, butyl xanthate according to 3:1 ratio) as a collector , pine oil as a foaming agent; The separation of copper and sulfur by flotation uses lime as an inhibitor to suppress sulfur, and the collector is a mixture of B, butyl xanthate (3:1), Z-200 and SN-9.
In the production, with the change of ore properties, the operators of copper-sulfur mixed operation always control the dosage of the chemicals too much. Although re-grinding, the sulfur in the copper-sulfur separation operation is still difficult to suppress. This will inevitably increase the amount of lime and float at too high a pH, so sometimes the sulfur concentrate has a copper grade of up to 0.5% and a copper loss of more than 20%. In view of the excessive use of chemicals in the copper-sulfur mixed operation, the method of adding activated carbon to remove the drug before re-grinding is adopted. After adopting this method, the copper concentrate grade has been improved to a certain extent, but the copper grade of the sulfur concentrate is still high. In addition, the preparation and addition of activated carbon are inconvenient, and also affect the civilization and hygiene of the plant.
3. Production practice of new technology
3.1 Formation of new processes [next]
In-depth and meticulous analysis and research have been carried out on the problems existing in production. The symbiotic relationship between copper, gold, silver and sulfur minerals in ore is extremely close, and it is difficult to fully dissociate.
The original two-stage grinding copper-sulfur separation flotation process is the return sequence of the medium-mine sequence. Previously, there was no practical problem that a considerable part of the useful minerals in the middle ore still existed as a continuous organism. In the flotation operation, a considerable number of continuous pigs were eventually suppressed and entered the sulfur concentrate. A number of process investigations and product screening analysis found that the +74μm coarse-grain grade copper grade in the sulfur concentrate is high, generally above 0.3%.
The final dissociation of the original minerals is completely dependent on the re-grinding of the copper-sulfur mixed concentrate. In actual production, the embedding granularity of the useful minerals varies according to the nature of the ore, and the state of the equipment is also different. It is not the first time that grinding can achieve the best effect of mineral dissociation.
3.2 Characteristics of the new process
First of all, the new process combines the actual conditions of on-site production, which is conducive to the grading and re-grinding of ungrounded continuum, which makes the dissociation of copper, gold, silver, sulfur and other minerals more complete, and the effect of copper and sulfur sorting is obviously improved. . Screening analysis showed that the crude copper grade of +74μm in the sulfur concentrate decreased to about 0.2%, which reduced the loss rate of copper in the sulfur concentrate. Secondly, the on-site reconstruction has a small amount of engineering and is easy to implement, making full use of the remaining amount of the existing medium and mine regrind equipment. Third, the flotation process is stable and easy to operate. The copper-sulfur separation operation does not directly return to the rough selection, which makes the coarse and fine selection work more stable, so that the whole copper-sulfur separation operation is more stable and is conducive to operation.
3.3 Apply the effect of the new process
(1) The beneficiation index has been significantly improved. The indicators before and after the process improvement are shown in Table 1. Here is a comparison between January-November 1999 and January-November 2000.
Table 1 Comparison of indicators before and after process improvement /%
project | January to January 1999 | January to November 2000 |
Cu | S | Au | Ag | Cu | S | Au | Ag |
Raw ore grade Copper concentrate grade Sulfur concentrate grade Tailings grade Recovery rate | 0.407 18.535 0.315 0.030 80.11 | 8.335 34.796 39.412 0.744 85.50 | 0.33 7.70 0.91 0.04 40.84 | 13.9 320.9 36.3 2.2 40.52 | 0.475 19.538 0.278 0.036 83.31 | 8.846 34.973 41.010 0.823 84.56 | 0.39 8.96 0.95 0.04 46.65 | 14.2 324.4 29.6 2.8 46.43 |
Raw ore processing capacity / t | 222949.7 | 275909.2 |
Gold and silver grade units are g/t
It can be seen from Table 1 that the copper concentrate grade increased by 1.003% after the process improvement, and the recovery rates of copper, gold and silver increased by 3.2%, 5.81% and 5.91%, respectively, and the index increase was very obvious.
(2) Simplified the pharmaceutical system and saved the cost of pharmaceuticals. After the improvement of the process, with the improvement of the index, the attempt to streamline the added chemicals and gradually cancel the activated carbon and SN-9, which not only simplifies the pharmaceutical system, but also saves the cost of the medicament, and the sanitary condition of the plant is also improved, which is beneficial to the improvement. Create leak-free and standardized plants.
(3) The concept of operation of the operator has been changed. For a long time, the operator has formed a habit of using high collectors and high inhibitors. After the process improvement, the operator found in the operation that not only the index is easy to grasp, but also the dosage of the medicament is greatly reduced, and the operation is stable. Using the original strong pull and strong pressure method and taking medicine, it is hard, and the indicators are still not up.
4, the conclusion
Practice shows that the crude sulfur mixed flotation system of the Yinshan lead-zinc mine copper-sulfur system originally used, the mixed concentrate re-grinding and re-election process, the grinding force is not enough, the mineral dissociation is not enough, and the mineral processing index is not high. By adopting measures to increase the separation of copper and sulfur from the selection of tailings into regrind, the regrind is strengthened and ensured, the effect of copper and sulfur sorting is improved, and the production index is significantly improved. At the same time, the type and amount of the medicament are reduced, which facilitates the operation. This experience is worth promoting.
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