The vast majority of non-ferrous metal sulfide ore processing by flotation, but if a larger proportion of useful minerals, coarse cloth inlay, also may consider re-floating joint process.
Therefore, the ore dressing test should first determine the possibility of re-election based on the specific gravity of the mineral and the size of the inlay, and if necessary, the heavy liquid separation test, and then select the flotation process and prescription according to the mineral composition and related physical and chemical properties.
(1) Copper sulfide ore
The beneficiation test of copper sulfide ore without oxidation (very low oxidation rate) can basically only consider the flotation scheme.
In copper sulfide ore, in addition to copper sulfide minerals and gangue, there are some iron sulfide minerals (pyrite), pyrrhotite, arsenopyrite, etc., and the separation of copper sulfide minerals from gangue It is relatively easy, so the main contradiction of copper sulfide ore flotation is copper and sulfur separation.
When the content of iron sulfide minerals in the ore is high, the preferential flotation process should be adopted; conversely, the process of separation after copper-sulfur mixed flotation should be given priority, but the preferential flotation process is not excluded.
The basic prescription for the separation of copper and sulfur is to suppress the iron sulfide mineral with lime and, if necessary, to add a small amount of cyanide. Resurrection iron sulfides available sodium carbonate, carbon dioxide gas, sulfuric acid, etc., while the need to add a small amount of copper sulfate.
When the ore contains magnetite, it can be recovered by magnetic separation.
When the ore contains cobalt, the cobalt is generally present in the pyrite, the pyrite concentrate is cobalt concentrate.
When the ore contains a small amount of molybdenum , the copper-molybdenum mixed concentrate may be first selected and then separated.
Most of the copper- nickel ore is a mixed flotation process. The mixed concentrate can be first smelted into nickel ice copper and then separated by flotation, or directly by flotation.
(Ii) zinc copper sulfide ores
The copper sulfide zinc ore is mainly treated by flotation.
The copper sulfide zinc ore usually contains iron sulfide minerals. The main task is to solve the flotation of copper, zinc, sulfur separation, particularly lead zinc separation problems.
Since copper-zinc minerals are often densely symbiotic, and sphalerite is easily activated (in the ore or in the slurry) by copper ions, copper-zinc separation is usually more difficult than lead-zinc separation.
The flotation process needs to be tested and compared, but it can be judged based on the composition of the ore material. When the content of sulfide is high, priority should be given to the partial flotation process after preferential flotation process or copper-zinc mixed flotation, and then the whole flotation process may be considered, or zinc-sulfur mixed flotation after preferential floatation. . When the particle size of the copper mineral and the zinc mineral symbiosis with each other is finer than the particle size of the symbiotic with the pyrite, a copper-zinc partial mixed flotation process can be used; conversely, it is better to float the copper and then float the zinc.
The basic prescription for the separation of copper and zinc is still the use of cyanide or sulfite (including NaSO3, Na2S2O3, NaHSO3, H2SO3, SO2 gas, etc.) zinc-suppressing copper, mostly mixed with zinc sulfate. Also consider trying the following three options:
1. Sodium sulfide plus zinc sulfate and zinc floating copper;
2. In the lime medium, use red blood salt to suppress copper floating zinc;
3. Warm the slurry in the lime medium (to 60 ° C) to suppress copper floating zinc.
The traditional prescription for the separation of zinc and sulfur is to use lime to suppress sulfur and float zinc. In areas where conditions permit, it is also possible to try to use the slurry heating method instead of lime to inhibit pyrite.
(3) Copper sulfide lead-zinc ore
The beneficiation of copper sulphide lead-zinc ore is also mainly carried out by flotation. The following two process scenarios should be prioritized during the test:
1. Partially mixed flotation process, that is, first mixing flotation copper and lead, and then sequentially or mixing flotation zinc and sulfur minerals.
2. The mixing flotation process is to float all the sulfides once and then separate them.
Copper-lead separation is a major problem in the flotation of copper-lead-zinc ore. The solution can be lead-free copper or copper-lead. If that plan is better, it must be determined through specific tests. However, the general principle is: when the content of lead in the ore is much higher than that of copper, the copper should be suppressed. Otherwise, when the copper content is close to or in the form of lead, copper should be floated.
Common copper and lead separation methods are as follows:
(1) a heavy chromate method: i.e. dichromate suppress flotation of copper minerals and galena.
(2) Cyanidation method: the use of cyanide to suppress copper minerals and flotation of lead minerals.
(3) Ferricyanide method: When the secondary copper mineral content in the ore is high, the effects of the above two methods are not good enough. At this time, if the lead content in the ore is high, ferricyanide (yellow blood salt) can be used. And red blood salt) to inhibit secondary copper mineral flotation lead minerals; if the lead content is much higher than copper, the following two options should be tested.
(4) Sulfuric acid method (sulphur dioxide method): The mixed concentrate is treated with sulfur dioxide gas or sulfurous acid, so that the lead mineral is inhibited and the copper mineral is activated. In order to strengthen the inhibition, potassium dichromate or zinc dithionite may be added, or the slurry may be heated (heated flotation method), and finally the pH of the slurry must be adjusted to 5-7 with lime, and then copper is used. Flotation of minerals.
(5) Sodium sulfite, iron sulphate method: that is, sodium sulfite and iron sulphate are used as a mixed inhibitor, and the slurry is acidified with sulfuric acid, stirred under the condition of pH=6-7, and the galena is inhibited to float the copper mineral.
One of the main reasons for the difficulty in separating copper-lead mixed concentrates is due to the presence of excess chemicals ( collectors and foaming agents) in the mixed concentrate. Removal of excess agent from the slurry prior to separation of the concentrate and removal of the collector film from the mineral surface can greatly improve the separation of the mixed concentrate.
Methods for removing excess pesticide from the slurry and removing the collector film from the mineral surface are:
1. Mechanical method;
2. Chemical or physicochemical methods. The appropriate method can be selected depending on the nature of the mixed concentrate and the conditions it obtains.
In polymetallic ores, the recovery of associated useful minerals depends on their symbiosis with the major minerals and the behaviour during the sorting process. For example, bismuth and strontium mainly enter lead concentrates, which can be recovered during smelting. Cadmium , indium and antimony, etc., are usually symbiotic with sphalerite and may enter zinc concentrates. Cobalt enters the pyrite concentrate during the sorting process, but may also enter the copper and zinc concentrate. Molybdenum and tin are sometimes selected as individual products or semi-finished products. Gold and silver are often combined with sulfide ore and selected into the corresponding concentrates, and generally enter the lead concentrate more.
Second, the main program for the selection of copper oxide ore
The main schemes for selecting copper oxide ore at home and abroad are summarized as follows:
(1) Flotation method: direct flotation, vulcanization flotation, etc.
(2) Water-smelting method: ammonia leaching method and acid leaching method.
The first type is leached with sulfuric acid, then the copper is replaced with iron filings, and the precipitated copper is floated by flotation.
The second is leached with NH3, CO2, sulfur (sulfur, pyrite, etc.) precipitates copper sulfide and then floats.
(3) Segregation-flotation method.
(4) Bacterial leaching method.
At present, the mines that have been put into production in China have been pre-vulcanized with sodium sulfide and then sorted by a single flotation method. However, it is difficult to recover the refractory copper oxide ore by single flotation. In order to solve the utilization of this part of the resources, more researches have been carried out. The general trend is to use the beneficiation-metallurgical combined process or metallurgical method. Abroad also the case, easy to handle Oxidized Copper also mainly flotation of refractory oxide copper ore is mostly joint process.
Third, the choice of test plan
This major ore sorting objects into copper oxide and pyrite, have tried first single flotation process, including flotation and bulk flotation process. It has been proved by practice that a single flotation scheme cannot be used, and satisfactory indicators cannot be obtained.
The understanding of the nature of the ore cannot be completed before the test. To truly understand the characteristics of the ore studied, it is ultimately necessary to rely on its own practice. After practice, understanding, practice, and recognizing, it is found that in the case of coarse ore, most of the copper oxide ore can be dissolved by water or dilute acid, and when it is finely ground, it is insoluble. The reason is that the mine contains a lot of limestone and other alkaline gangue. These gangues are not only bad for water smelting, but also cause the dissolved copper to re-precipitate, which makes water smelting and flotation difficult. This special rule of ore is mainly due to the fact that the copper oxide ore is in the oxidation zone of the sulfide deposit, and most of the ore and gangue are weathered as loose powder, which is caused by severe weathering. Mastering this rule of ore, we must make our own thoughts conform to the regularity of this objective outside world, change the original plan, and redefine the following scheme:
(1) Acid leaching-flotation (leaching flotation).
(2) Water immersion-flotation (leaching flotation).
The mine adopts a combined water-smelting-flotation process, which not only improves the copper index, but also improves the flotation of the leaching residue. However, due to the high content of pyrite in the ore, if the flotation is directly precipitated in the leaching pulp, the separation of copper and sulfur is difficult, so the method of separately treating the slag should be adopted. Since the ore contains a large amount of limestone , the leaching particle size cannot be used for flotation granularity, and the weathering property should be utilized to use coarse leaching. The water smelting process can be leached with water, and a 0.3%-1.0% dilute acid solution can also be used. Although the leaching rates of the two are quite different, the final indicators are very close.
The copper in the immersion liquid can be recovered by a general method such as iron powder replacement, sodium sulfide precipitation, or the like, and can also be extracted with an extracting agent to be concentrated and directly electrolyzed to produce electric copper. Fatty acid extraction was used in the test. (In the experiment, N510 extractant, ie, a-hydroxy 5 sec-octyl benzophenone oxime) was used, and good results were obtained.
From the process and method that has been done, the combined process of water and metallurgy-flotation is an effective method to treat this mine. Both water immersion-flotation and acid leaching-flotation can obtain satisfactory indicators.
The recommended treatment scheme has a coarse leaching particle size, a short leaching time, and no acid. This will be carried out automatically in the future washing process, so it is suitable for both ore properties and future production. However, due to the lack of production practices, further verification is required by expanding the trial.
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