Dry goods! The "Manganese Carbonate" Concentrator teaches you how to choose manganese ore!

Manganese carbonate ore beneficiation plant - Zunyi manganese Concentrator

Most of the manganese carbonate ore beneficiation methods use strong magnetic separation, heavy medium ore dressing and flotation. Sulfur-containing sedimentary carbonate ores generally in accordance with carbonaceous shales, and pyrite sequence thereof using manganese flotation process. Hydrothermal zinc carbonate ores containing lead generally a magnetic beneficiation flotation process. Some sulfur-rich manganese ore, manganese minerals are mainly sulphur-manganese ore, and generally use roasting to remove sulfur. Some manganese carbonate-rich ores are also produced by roasting to remove volatile components to obtain finished ore.

1 Beneficiation overview

Zunyi ferroalloy limited liability company Zunyi City, Zunyi manganese ore dressing plant located in South East Causeway well, from Zunyi City, 6km, 9km transportation is very convenient from the Sichuan-Guizhou Railway Station just south iron.

The Zunyi Manganese Mine Area includes Tongzijing, Shaba, Changgou, Huangtukan, Pomegranate Ditch and Shenxigou. The Tonglujing and Shaba ore sections have been explored, and the remaining sections are only for detailed investigation and census work. The mining area is 10km long and has an area of ​​16km2. The ore deposit occurs at the bottom of the Upper Permian Longtan Formation and is strictly controlled by the stratigraphic layer. Manganese carbonate ore is produced in gray shale. In the 2005 Mineral Resources Reserves Review Table of the Ministry of Land and Resources, the Zunyi manganese ore-related ore section maintains a resource reserve of 23 million tons of manganese ore.

Lawrence Tongluojing manganese ore mining accounted for 75% of the overall resource reserves, manganese ore grade of 15% to 25%, 9% and 10% iron, phosphorus-containing an average of 0.046%, sulfur 4.43% on average, are Low-manganese, low-phosphorus, high-iron, high-sulfur semi-self-fluxing manganese ore. The mining area is located in the hilly and mountainous areas of the plateau. The elevation of the surface ore body is 980-795m, and the ore body depth is 0-606m. Except for the shallow oxidized ore, the other shafts need to be developed and underground. The mining layer has good continuity, thickness and grade stability, and the change of the mineral layer is small.

The Zunyi Manganese Ore Concentrator was founded in 1958. In 1974, the mining, selection and burning project was initially completed and put into operation. The flotation column was originally designed as a flotation unit for the whole float process. Due to the soft and brittle manganese ore, two sections of continuous grinding Serious over-grinding, excessive secondary sludge, demineralized manganese metal loss rate exceeds the original design, total manganese metal recovery rate does not meet the design requirements, after years of technical transformation, the formation of two-stage grinding-magnetic separation-flotation In the process, when the ore contains Mn of 18%, the manganese concentrate is selected to contain Mn 25% to 26%, which is filtered and sent to the pelletizing workshop for batching, pelletizing, and then sintering (small ball) sintering and sintering. The ore contains Mn 32% to 34%, and it is used as a clinker for smelting manganese-based ferroalloys in the Zunyi Ferroalloy Plant.

2 ore properties

The ore has two natural types of manganese oxide ore and manganese carbonate ore.

Manganese oxide ore is a product of oxidative enrichment of manganese carbonate ore, which is distributed near the surface, accounting for 5.85% of proven reserves, and only 1.45% of retained reserves. At present, manganese oxide ore has been mined in various parts.

Manganese carbonate ore is composed of calcium rhodochrosite, rhodochrosite, manganese calcite , manganese-containing calcite, manganese dolomite, manganese siderite, iron ore, ore, manganite, manganite, pyrite, manganese-containing siderite and Water mica , chlorite, chlorite, kaolinite, dolomite, quartz , feldspar, etc. The main ore mineral is mainly calcium rhodochrosite, and its content accounts for 82%-83% of the total amount of carbonate minerals. The ore has sand gravel, spherules, bioclastics and grain structure, with a layered, micro-layered, intermittent layered, lace-like and grape-like structure. The lower part is mainly composed of microcrystalline-pellet structure, microlayer and intermittent layer; the upper part is sand-gravel structure, lace-like, grape-like and porous structure. The ore manganese grade is 8% to 32%, mostly 15% to 32%, with an average of 20.29%, and the manganese grade variation coefficient is 13.9% to 19.2%. The grade of ore is relatively stable, and there is no major change along the trend or tendency; from the bottom to the top, manganese, sulfur and calcium have a decreasing trend.

The genetic type of the deposit belongs to the marine sedimentary manganese deposit produced in the Upper Permian clay rock; the industrial type belongs to the low-phosphorus high-iron and high-sulfuric manganese-poor ore.

The chemical composition analysis of the ore is shown in Table 1, and the phase analysis of the ore is shown in Table 2. The rhodochrosite in the ore is mostly in the form of fine-grained aggregates and dense blocks. Calcium-manganese ore has a layered structure, and manganese calcite appears as crystal aggregates or fine veins. The particle size of the manganese mineral aggregate or monomer is generally 0.02 to 0.2 mm.

The ore density is 3300kg/m3, the Platts hardness is 6-8, and the ore water content is 4%-6%. The physical properties of different minerals are shown in Table 3.

Table 1 Results of chemical composition analysis of Zunyi manganese ore

Table 2 Analysis of manganese and iron phases in Zunyi manganese ore

Table 3 Physical properties of main minerals in the Lianyi manganese ore

3 Mineral processing plant technology progress

The Zunyi manganese mine began construction in 1958, and in 1975 it was built into a production scale of 600,000 tons/year. The process of the concentrator includes crushing, grinding, flotation, concentration and filtration. The crushing consists of coarse crushing, sieving, washing and closed-circuit crushing operations. The sorting operation is a full-floating process in which the flotation column is used as a flotation device. After the ore is crushed, it is subjected to two-stage grinding to -0.074mm, which accounts for 85%. The mud is de-sludged by a φ125mm hydrocyclone, and the grit is put into flotation. In the flotation operation, the first choice is to use the No. 2 oil to select the carbon, and then the yellow medicine to float the pyrite. Finally, the oxidized paraffin soap is used to select manganese in the slurry in which sodium carbonate is used as a regulator and water glass is used as an inhibitor. Concentrate products are Grade I, II and III manganese concentrates and by-product pyrite concentrates.

The total amount of raw ore medicinal agent is designed to be 7.5 kg/t, and the actual production is generally 10 kg/t. After several years of trial production, it has been abnormal, and the product quality and recovery rate have not met the design requirements. The main reason is that the ore is seriously muddy during the crushing and grinding process. The φ125mm hydrocyclone before the flotation has poor mud removal effect and the manganese metal loss is serious. The concentrate grade does not meet the design requirements, and the actual recovery rate of mineral processing is generally only 50% to 60%.

Subsequently, the relevant units conducted a pilot study, and changed one of the three series of the original cyclone desliming-flotation series into a strong magnetic-selection process. Using the Shp2000 strong magnetic separator to remove mud and improve the manganese grade, the flotation equipment was changed from a flotation column to a flotation machine. In addition, the manganese-selective collector was changed from the original oxidized paraffin soap to a mixture of sodium petroleum sulfonate and oxidized paraffin soap. The testing process of the mineral processing industry is shown in Figure 1. The industrial test indicators for the single flotation process and the strong magnetic-flotation process are shown in Table 4.

Figure 1 Mineral processing industry test process

Table 4 Beneficiation index of Zunyi manganese ore dressing plant

The magnetic separation-flotation combined process has better adaptability. The strong magnetic separator not only effectively removes the slime, but also plays a good role in improving the selected manganese grade of flotation. In the production, strong magnetic-flotation desulfurization is sometimes used to directly obtain the integrated manganese concentrate product; Sodium instead of oxidized paraffin soap as a collector, the pulp is sorted at neutral and normal temperature, saving drug consumption and energy consumption, and improving the dewatering performance of the concentrate; the sodium carbonate adjusting agent used in the original process is eliminated in the new process. , thereby reducing the cost of the pharmacy.

During the magnetic-floating process industry test, the Shp strong magnetic separator was once used as the rough selection, and the lower plate was used as the sweeping. The two-stage sorting operation of one machine was tried, and the phenomenon of “diffuse mine” appeared on the plate. The method of reducing the amount of ball milled ore was reduced to ensure its smoothness. At that time, the yield of magnetically selected concentrate products basically met the requirements of industrial tests. After the end of the industrial test, the upper and lower plates are still used for rough selection, which can increase the amount of ore, which has been used until l998.

After a section of magnetic separation, the manganese grade of tailings is between 10% and 12%. When the ore grade is high, the tailings are still too high, resulting in a magnetic separation concentrate yield of 65% to 72% 徘徊, magnetic separation. After the concentrate is subjected to flotation, dehydration and other operations, some tailings must be thrown off in each section. When the final product is filtered, the manganese concentrate yield is reduced to 45% to 50%, and the ore washing is carried out after the original ore crushing and screening. The yield of 3% to 5% lost in the operation, the actual yield of the final concentrate is lower, generally 42% to 45%, and the actual recovery rate of manganese is 58% to 61%.

In July 1998, through a pilot study, a coarse and a sweep two-stage selection was started on the Shp-2000 magnetic machine. The measures taken at the same time are:

(l) Appropriately increase the magnetic separation to the ore concentration, and increase the original concentration of 20% to 22% to 30% to 35%.

(2) Reducing the grinding fineness, from the original -0.074mm content from 72% to 78% to 60% to 65%, as the fineness becomes thicker, the graded overflow concentration is also ensured.

(3) Adjust the clearance between the upper and lower disc plates. The upper disc is thick with a 3.2mm clearance tooth plate or movable tooth plate. The lower plate sweep uses a 2.8mm tooth plate, which ensures that the upper plate can pass more mines. The quantity also ensures that the magnetic field strength of the sorting area is appropriately increased in the lower plate, thereby facilitating the improvement of the recovery rate.

(4) Strengthen the operation of removing slag and removing iron, and often clear the blocked tooth plate to ensure the smooth passage of the slurry.

(5) As the concentration of the ore is increased and the fineness is reduced, the production capacity of the mill is also slightly improved, from 20t/h to more than 25t/h.

4 Production process and process

After more than 20 years of experimental research and technical transformation, Zunyi manganese ore dressing plant has formed a two-stage grinding-strong magnetic (one coarse one sweep)-flotation process. The selection indicators before and after the process improvement in 1998 are shown in Table 5. Shown.

It can be seen from Table 5 that the improved magnetic separation tailings grade is reduced by 2.32 percentage points before the improvement; the magnetic separation concentrate recovery rate is increased by 7.02 percentage points; in the case that the final manganese concentrate has little difference in manganese grade, the yield The increase was 6.88 percentage points, and the recovery rate increased by 7.66 percentage points. After the improvement, the selection index has been greatly improved.

Table 5 Selection indicators before and after the improvement of magnetic separation process

After the magnetic separation process was improved, the final manganese concentrate yield increased from 50.97% to 57.85% before the improvement, and the dressing ratio decreased from 1.96 before the improvement to 1.73.

The improved selection process is shown in Figure 2. The main equipment of the concentrator is shown in Table 6.

Figure 2 Improved selection flow chart

Table 6 Main equipment of Zunyi manganese ore dressing plant