Study on Improving Copper Index of Fenghuangshan Copper Mine

I. Introduction

Fenghuangshan copper ore beneficiation process is a semi-half priority flotation process, in recent years due to changes in the nature of the ore occurs, lower grade copper ore, sulfur-rise, leading to the production site has the following two problems: (1) in half flotation The effect of natural pH is very poor, the recovery rate of copper is gradually reduced from about 60% to about 30%; (2) the yield of mixed concentrate is too large, and the re-grinding of mixing has not reached the original design fineness. For this purpose, a pilot study was carried out to improve the semi-priority selection pH value and to re-grind the mixed concentrate in the field to the mixed concentrate and re-grind the coarse concentrate to obtain better results.

Second, the nature of the ore

(1) Mineral composition of ore

Fenghuangshan copper sulfide ore metal mainly chalcopyrite, bornite, pyrite, pyrite times as gum, a small amount of chalcocite, blue chalcocite, sphalerite, galena, white Iron ore; the main gangue minerals are quartz , calcite , sub- diopside , a small amount of garnet , dolomite, feldspar , chlorite, mica kaolin. The composition of the minerals is shown in Table 1.

(2) Distribution of the content of major metal minerals

The particle size distribution of the main metal minerals chalcopyrite, porphyrite, pyrite, and pyrite is shown in Table 2.

It is known from Table 2 that the size of chalcopyrite is mainly fine particles, supplemented by medium particles, and contains micron-sized types; the size of the bauxite is micro-grain type, and the bauxite is finer than chalcopyrite. In general, copper minerals are more dispersed and are unevenly distributed. They need to be segmented and ground, and sorted to prevent the coarse-grained grade from smashing and deteriorate the sorting conditions. Pyrite and rubber pyrite are in the middle and fine grain inhomogeneous type, and also need to be segmented grinding and segmentation. The pyrite is easily oxidized, resulting in good buoyancy. Therefore, it is necessary to increase the pH half-priority. To suppress the better floatability of sulfur.

(III) Chemical analysis of raw ore

The multi-element analysis of the ore and copper phase analysis are shown in Table 3 and Table 4.

Third, the experimental study to improve the process conditions

In view of the two problems in production, based on the starting point of on-site production management, the semi-priority selection conditions and re-grinding sites were studied on the basis of the original semi-primary and semi-mixed processes.

(1) Study on semi-priority adjustment of pH to inhibit sulfur

The process principle of the current process conditions is shown in Figure 1. The relationship between the semi-priority copper fine 1 index, the tailings index and the semi-priority pH value is shown in Figure 2 and Figure 3.

As can be seen from the above figures, as the pH value increases, the copper grade of the tailings decreases, and the semi-priority copper grade and recovery rate are higher than the natural pH value. The semi-preferable pH value is 11.0. Because the pH value is increased properly, the difference of copper and sulfur floatability is increased. At the same time, the ore contains a large amount of secondary copper sulfide, and the secondary copper sulfide is brittle and easy to be worn. Appropriate increase of the semi-priority pH value also strengthens the coagulation effect on the fine-grained copper minerals, and proper agglomeration increases the viscosity to facilitate flotation. Therefore, appropriately increasing the semi-priority pH value can effectively exert the selective collection effect of OSN-43, and at the same time, it is beneficial to the flotation of fine-grained secondary copper sulfide, so that the copper quality and recovery rate of the semi-priority flotation portion can be improved. At this pH value, sulfur is not strongly inhibited, and it can still be floated by Dinghuang, so it will not affect the semi-mixed flotation, and the total index of copper and sulfur can be improved.

(2) Research on improving the refinement and fineness of mixing

Aiming at the second problem existing in the field, under the premise of improving the semi-priority pH value of the site to improve the recovery rate of the semi-priority copper concentrate 1, the change of the re-grinding location of the mixed concentrate and the improvement of the re-grinding degree of the mixed concentrate were made. Experimental study, the experimental mixed concentrate separation part is shown in Figure 4, the other parts are still the process shown in Figure 1, the test indicators are shown in Table 5.

It can be seen from Table 2 that the pyrite and rubber pyrite have a coarser grain size, the pyrite +0.074mm particle size is 70.32%, the +0.037mm grain size is 85.87%, and the rubber pyrite +0.074mm grain size accounts for 79.89. %, 0.037mm grain size accounted for 91.55%. When the fineness of grinding is -0.074mm and 70% is 70%, most of the monomers have been dissociated. Therefore, in the separation of copper and sulfur, the sulfur which has been dissociated from the monomer can be separated first to avoid the separation of copper and sulfur by over-grinding. Bringing impact and reducing the amount of re-grinding work. Therefore, the problem that the regrind fineness does not meet the requirements is solved, and the separation efficiency of copper and sulfur is improved.

Fourth, closed circuit test

The closed-circuit test was carried out on the on-site original process to increase the semi-priority pH value and the copper-sulfur separation coarse and fine regrind process to verify whether the improved process can effectively solve the problems in the field. The closed-circuit test indicators of the two processes are shown in Table 6.

V. Conclusion

(1) The semi-priority plus lime appropriately raises the pH value, increases the difference in floatability of copper and sulfur, and also strengthens the agglomeration of fine-grained copper. When the semi-priority partial flotation pH was increased from 7.4 to 11.0, the recovery rate of the semi-priority copper concentrate 1 was increased from 29% of the on-site process to 63.81%.

(2) Compared with the on-site process, the mixed concentrate is first separated, the coarse concentrate is separated and reground, and the regrind fineness problem is solved. The sulfur concentrate has low copper content; at the same time, the regrind amount is reduced, and the sulfur concentrate is improved. The particle size composition makes the ore concentrate easier to dewater. Increasing the semi-priority pH value, the semi-priority semi-mixed copper ore separation copper concentrate concentrate regrind process compared with the on-site process, the total copper concentrate grade and copper recovery rate increased by 0.59% and 2.5%, respectively, and the sulfur selection index also improved.

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