Separation process characteristics of refractory manganese oxide ore

I. Overview

Mud phenomenon manganese oxide ores are generally more serious, and some of the ore is easily cracked mud under the mechanical action, and manganese in the rough, the difference in the content of the fine fraction is larger, therefore, not only in its sorting process Consider de-sludge, and according to the nature of the ore, avoid unnecessary mechanical action to cause further muddy of the ore. Sorting at coarse and medium particle sizes often leads to better selection criteria than fine grinding and deep selection, and the process is very simple and the technical and economic indicators are good. This is developed in recent years, "refractory oxide ore beneficiation of coarse aggregate" of new technology.

According to the author's manganese ore dressing practice for many years, several major problems in the selection of manganese oxide ore are difficult to select, and a preliminary discussion and discussion are made.

Second, reasonable increase in the selected size, to avoid the production of secondary slime

Manganese oxide ore, especially pulverized manganese ore, is extremely easy to be secondary to mud. Because such manganese oxide ore is often very fine in size, the degree of dissociation may not be greatly improved after the particle size is reduced, but the separation process is deteriorated. Therefore, when determining the selection scheme, the manganese-rich aggregate particles should be protected according to the nature of the ore, and the mechanical action should be avoided to cause cracking and muddy, which makes it difficult to recycle.

The main manganese mineral of Muguisong pyrolusite in Guangxi is meta-manganese ore, and the gangue minerals are mainly quartz and clay minerals. The ore has low hardness, small body weight and serious muddy. The meta-manganese ore is mixed with the mud, and the mud is concentrated in the pores of the meta-manganese ore, or adheres to the surface of the manganese aggregate, and the ore has a moisture content of about 50%. Due to the strong magnetic separation or flotation of conventional crushing and grinding, due to the above factors, not only the selection index is not ideal, but also difficult to achieve in industrial production.

According to the characteristics that the muddy matter and the manganese aggregate are not tightly adhered. The self-friction solution is used to dissociate the manganese mineral aggregates from the gangue mineral deposits such as clay, and then the manganese-rich aggregates and the slime are sorted by classification. The industrial test indicators for the four mineral samples of Muguisson Pyrolusite using the simple process shown in Figure 1 are shown in Table 1.

Figure 1 Self-grinding and decanting process

Table 1 Four kinds of ore samples self-grinding and dissolving and selecting comprehensive concentrate index %

Note: The unit of Ag is g∕t

The process does not need to be broken, and the ideal industrial test index is obtained only by the self-grinding-washing classification. This process is used for ores of this nature, which is not only simple in process, low in production cost, but also reasonable and reliable.

Fujian Longyan Huangjiao Manganese Oxide Mine is also a loose or highly muddy ore. The results of the sieve analysis of the raw ore only after stirring by a stirrer are shown in Table 2.

Table 2 Screening results of raw ore after mechanical agitation

The results show that the coarse-grained grade contains high manganese and the fine-grained grade contains low manganese. However, the yield of the coarse fraction is small, the yield of the +0.5 mm grade is only 23.13%, and the yield of the slime of -38 μm is as high as 46.05%. It can be seen that the degree of muddy of the ore is very serious.

It has been found through experiments that a considerable part of the slime is produced by agitation and sieving. By reducing the stirring strength, the particle size of the manganese aggregate can be protected, and the classification test results of different stirring strengths are shown in Table 3.

Table 3 Different mixing strength classification test results of ore

The test results show that the yield of +0.5mm grade is obviously decreased after the strong ore is stirred, the manganese grade is not improved, and the yield and manganese grade of -0.5mm grade are greatly improved. At the same time, it also shows that the light ore mixing of the ore can protect the coarse aggregate, avoid the role of ore mud, and at the same time make the ore dispersed.

Using the process shown in Figure 2, when the concentrate grade is about 36%, the light agitation process is 7% higher than the strong agitation process, which is about 72%. The results of continuous expansion of the ore dressing are shown in Table 4.

Table 4 Expanding the test station indicator %

Figure 2 small test process

The continuous expansion of the test results shows that its comprehensive selection index is better than the small test. This is because of the light (manual) agitation and mechanical grading of a large number of ore, which has less mechanical damage to the ore and lower classification efficiency, which leads to a significant increase in the coarse fraction yield, which is conducive to the improvement of concentrate recovery, but Concentrate grade has an impact.

Third, the use of grading process to simplify the selection process

The self-grinding and dissolving-washing grading of the Muguisong soft manganese ore in Guangxi and the washing and grading of the slanting manganese ore-strong magnetic separation process all adopt the classification operation as the sorting process. For the Muguisong pyrolusite ore, since the ore contains very few coarse gangues, the ore is obtained by self-grinding-washing and classification, and the final concentrate is obtained. This washing and grading coarse-grain concentrate was selected in the industrial test of 801 and CS-1 industrial type coarse and medium-grain strong magnetic separators of Guangxi Bayi Manganese Mine, and the concentrate grade can only be increased by 1% to 2%. And the job recovery rate is reduced by 20% to 25%. It can be seen that the level of concentrate of such ore is related to the selection process and the manganese content of the aggregate itself. For this ore utilization classification as a sorting process, the comprehensive mineral processing index is not worse than the strong magnetic separation, and can greatly save investment and simplify the process.

The grading operation of the slanting manganese ore mine has played a rough selection role for the strong magnetic separation of the induction roller, and also plays a role in improving the selection environment for the entire process. Because it is not classified, it can directly reach the induction roller for strong magnetic separation, and can only achieve the concentrate index of 38.54%, manganese grade 29.11% and recovery rate 51.58%.

The results of particle size classification of fine and tailings are shown in Table 5.

Table 5 Fine and tailings classification test results %

The results show that the reason why the manganese grade of concentrate is not high is that a large amount of low-grade ore is brought in, and the recovery rate is not high, mainly because the fine-grain grade is not effectively recovered, and some coarse manganese-rich aggregates are lost. In the tailings. With the classification process, the manganese grade of 7-0.5mm grade can be increased from 21.80% to 31.79% of the original ore, and then selected by induction rolls, the manganese content of the concentrate is up to 41.29%, and the operation recovery rate is about 95%. The tailings contain only 6% to 7% of manganese, and the fine-grained grades can be obtained with fines containing more than 30% of manganese after one-time selection by a fine-grained magnetic device-like Jones magnetic machine. It can be seen that the grading process plays a dual role in grading and rough selection.

Guangxi Longan Phoenix Mountain Silver- manganese Mine, the ore contains only 7% manganese, and the silver content is higher, 240g / t. Clay minerals serious, mainly silicon aluminum gangue mineral salt.

Using the simple process shown in Figure 3, the concentrate 1: yield 12.91%, manganese grade 40.27%, recovery rate 74.36%; concentrate 2: yield 6.48%, manganese grade 25.15%, recovery rate 23.28% The ideal index, concentrate 1 and concentrate 2 also obtained silver 1156g / t, 1080g / t, the total recovery of silver was 91.72%.

Figure 3 Longan silver manganese ore separation process

The results of the induction roll magnetic separation concentrate screening are shown in Table 6. The results show that with 0.15mm as the separation particle size, the concentrate can be de-sludged, which can increase the manganese grade of concentrate by 10%, the operation recovery rate is over 97%, and the silver is further enriched in manganese concentrate. The grading process has played a very effective role in the selection.

Table 6 Inductive Roller Magnetic Separation Concentrate Screening Results %

Note: *The unit of silver is g∕t

Goldin for manganese ore smelting manganese-rich slag obtained crude silver alloy, the silver is recovered.

Fourth, the conclusion

Through the description of several difficult-to-select manganese oxide ore deposits, it can be summarized as follows:

(1) For manganese oxide ore with serious mud and loose structure, generally the coarse-grained manganese is high and the fine-grained manganese is low. According to this feature, coarse-grain manganese aggregate beneficiation should be carried out. In the process of sorting, damage to manganese aggregates caused by mechanical action such as crushing, strong agitation and strong scrubbing should be avoided as much as possible;

(2) Grading process In the beneficiation of manganese oxide ore, it is often the ideal sorting index that is difficult to obtain in other heavy and magnetic separation equipment ;

(3) Reasonable coarse-grained aggregate beneficiation process can simplify the beneficiation problem of refractory lean manganese oxide ore with serious muddy. It has many advantages such as simple process, low investment, easy operation, advanced indicators, and easy implementation in industry. At present, many manganese oxide plants in China use the principle process scheme of “coarse aggregate dressing”.

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