CN112044927A

CN112044927A - Full tailings grading and segmenting multi-way comprehensive utilization method

Info

Publication number: CN112044927A
Application number: CN202010816391.XA
Authority: CN
Inventors: 朱继生; 武培勇; 张亚海; 王周和; 陈锦安; 代献仁; 丁鹏
Original assignee: Tongling Nonferrous Metals Group Co Ltd
Current assignee: Tongling Nonferrous Metals Group Co Ltd
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2020-12-08

Abstract

The invention relates to a full tailings grading and multi-path comprehensive utilization method, which takes coarse fraction (+ 0.037 mm) tailings as filling sand for underground filling; fine-grained tailings of-0.037 mm- +0.01mm are used as an iron correction agent for a cement plant for external sales, and fine-grained tailings of-0.01 mm are subjected to flocculation precipitation and concentration and are transported to an earth and rockfill field for greening, so that waste is changed into valuable, 100% of mine tailings are recycled, and the generated wastewater is completely returned to be used as production water. The method has the advantages of simple process flow, convenient operation, high grading efficiency, environmental protection and considerable income, solves the problems of mine production tailing discharge and environmental protection, and also solves the problems of sand and soil for underground goaf filling and open pit environmental management, ensures normal production of mines, reduces yellow sand purchase amount and increases extra income.

Description

Full tailings grading and segmenting multi-way comprehensive utilization method

Technical Field

The invention relates to the field of mine ecological environment and tailing resource recycling, in particular to a full tailing grading and segmenting multi-way comprehensive utilization method.

Background

A new model national mine enterprise established by a certain mining company on the basis of the shutdown and the breakage of a certain original copper ore is provided, and the ore types of copper ore deposits are mainly copper-containing magnetite and copper-containing skarn ore. The main useful elements are copper, sulfur and iron; wherein the copper mineral is mainly brass, and then has the chalcocite, small-amount malachite and chalcopyrite; associated metal minerals mainly comprise siderite, magnetite, pyrite, hematite and the like; the gangue minerals mainly include skarn mineral, calcite, quartz, feldspar, etc. The mine mining (underground) adopts an upward separate mining filling mining method, and the mineral separation production principle flow is as follows: grinding (rod grinding and gravel grinding) classification (a swirler and a floating trough), copper semi-preferential copper selection, copper-sulfur mixed flotation, mixed concentrate regrinding, copper-sulfur separation flotation and mixed flotation tailing magnetic separator iron selection, wherein the products comprise three products of copper concentrate, sulfur concentrate and iron concentrate. The tailings are classified by two sections of cyclones, coarse tailings with the diameter of 0.037mm are used for filling underground, and fine tailings with the diameter of-0.037 mm are conveyed to a tailing pond for stockpiling. The main minerals in the tailings are calcite, quartz, muscovite, sericite, clinoptite, siderite, limonite, hematite, magnetite, pyrite, pyrrhotite, chalcopyrite and unequal clays, and no toxic and harmful components are found. The results of the multi-element analysis of the tailings chemistry are shown in table 1, and the composition of the particle size is shown in table 2.

TABLE 1 tailing chemistry multielement analysis results table

Element(s)

Fe

CaO

Al₂O₃

Mg

S

Cu

Content (%)

24.38

12.7

4.48

2.32

1.31

0.14

Element(s)

Zn

As

Ag

Au

Others

Total up to

Content (%)

0.035

0.011

7.17g/t

0.261g/t

24.98

100.00

As can be seen from the above table, the iron content in the tailings is higher than 24.38%, which is equivalent to Fe₂O₃It was 34.83%. Sulfur content 1.31%, equivalent to SO₃3.275%; and non-metal minerals such as silicon, calcium, aluminum and the like.

TABLE 2 complete tail particle size composition table

Serial number	Size fraction mm	Yield (%)	Cumulative yield (%)	Fe content (%)	Cumulative Fe distribution (%)
						1	+0.2	2.62	2.62	27.98	3.01
2	-0.2～+0.15	4.1	6.72	23.46	6.95
						3	-0.15～+0.10	12.25	18.97	19.87	16.94
4	-0.10～+0.074	8.11	27.08	20.14	23.63
						5	-0.074～+0.05	7.6	34.68	23.34	30.91
6	-0.05～+0.037	11.5	46.18	26.83	43.57
						7	-0.037～+0.027	13.4	59.58	30.72	60.45
8	-0.027～+0.020	13	72.58	26.21	74.43
						9	-0.020～+0.010	13.61	85.19	23.74	87.22
	-0.010	13.81	100.00	21.83	100.00
						Total up to		100.00		24.38

As can be seen from the particle size analysis, the distribution rate of the tailings with the particle size of 0.037-0.010mm is 40.01%, the iron-containing grade is high, and the distribution rate of iron is 43.65%.

At present, the tailings pond of the mining company cannot continuously pile the tailings due to the problems of environmental protection, full storage capacity and the like; the tailing grading efficiency is low, the yield of the coarse grain tailing with the grain size of +37 mu m cannot meet the underground filling requirement, a large amount of yellow sand needs to be purchased for filling, and the production cost is high; the open pit produced in the mine for years needs soil for landfill and greening. The above causes the enterprise to face the production stop. The specific defects are as follows:

1. the tailing pond used in the mine is a tailing pond used before a certain copper mine is closed, the tailing pond is located in a scenic spot 3.5 kilometers away from a selected factory, the area of the pond is 3 square kilometers, vegetation and a hillside soil body are damaged to a certain degree, sand leakage and dust raising events occur in the process, certain pollution is caused to the surrounding environment and a water source, certain harm is caused to the physical and mental health and life and property safety of people, and the environment protection and safety pressure is huge.

2. The tailing pond capacity used in the mine can not meet the service life requirement of enterprises, the newly-built tailing pond has huge investment, needs land acquisition and is high in cost, no place suitable for being used as the tailing pond is arranged at the periphery of the tailing pond, and the enterprises face the risk of production halt due to the fact that tailings are discharged everywhere.

3. The mining method of the mine is an upward horizontal mining filling mining method, the curing time of an underground filling body is required to be less than 48 hours, and researches show that the requirements can be met only if the content of the filling tailings plus 0.037mm is required to be more than or equal to 90%. Because of the low tailing grading efficiency, the produced coarse-particle tailing can not meet the filling requirement in quantity, and because the coarse-particle tailing contains a large amount of fine-particle tailing in quality, the strength requirement of a filling body can not be met. For this reason, enterprises need to purchase a large amount of yellow sand every year.

4. The iron, silicon dioxide, sulfur and other resources in the tailings are not fully recycled, so that the resource waste is caused.

Disclosure of Invention

The invention aims to provide a full-tailing grading and segmenting multi-way comprehensive utilization method which is simple in process flow, convenient to operate, high in grading efficiency, green, environment-friendly and considerable in income, coarse-particle tailings in tailings and resources such as iron and silicon dioxide in the tailings are fully utilized, a full-tailing grading multi-way tailing utilization complete process technology is formed, and the method comprises the following steps: the +0.037mm coarse grain tailings are used for underground filling, the-0.037- +0.01mm fine grain tailings are used as a cement production iron correction agent, and the-0.01 mm fine grain tailings are used for filling open pits and greening, so that 100% comprehensive utilization of the tailings is realized, and all generated wastewater is returned as production water. Thoroughly solve enterprise's tailings problem and environmental protection problem of going out of a way, ensure the normal production of mine.

The invention relates to a full tailings grading and segmenting multi-way comprehensive utilization method, which comprises the following steps:

A. reducing the content of harmful element sulfur in the tailings: in the sulfur flotation process, adding isobutyl xanthate into sulfur flotation ore pulp with the pH value of 6.5-7.5, wherein the addition amount of the isobutyl xanthate is 10-15 g/t;

B. separation of coarse fraction +0.037mm tailings: pumping mineral dressing tailing pulp with the mass concentration of 15-20% into an inclined plate thickener for concentration, entering a cyclone group for classification when the mass concentration of underflow pulp of the inclined plate thickener reaches 35-40%, and taking settled sand (the grain size is +0.037 mm) of the cyclone group as an underground filling material to be sent to an underground filling vertical sand silo;

C. improve Fe in fine fraction tailings of-0.037 mm- +0.010mm₂O₃The content of (A): b, overflowing the inclined plate densifier to remove Fe₂O₃Grading low-content non-metal minerals such as clay with a fine particle size of-0.01 mm and coarse quartz into settled sand, overflowing the cyclone group in the step B into a high-efficiency thickener to remove the clay with fine particles, and making Fe in the target particle size₂O₃Enriching;

D. separating fine fraction tailings with the size of-0.037 mm- +0.010 mm: b, feeding the material with the overflow particle size of-0.037 mm of the cyclone set in the step B into a high-efficiency dense precipitator for concentration, pumping the material into a filter for filtration when the mass concentration of underflow pulp of the high-efficiency dense precipitator is 60-65%, taking the obtained filter cake as a cement iron correction agent for external sales, and returning the obtained filter liquor to a system as production water;

E. separating fine fraction-0.01 mm tailings: b, conveying overflow liquid of the inclined plate thickener in the step B and the overflow liquid of the efficient thickener in the step C to an overhead thickener, and returning supernatant of the overhead thickener to a system to be used as production water; the bottom flow of the overhead thickener enters a sedimentation tank for solid-liquid separation, and the supernatant overflow of the sedimentation tank returns to the system as production water; the fine-particle tailings are obtained by concentrating and precipitating the flow at the bottom of the sedimentation tank and are used for filling open pits and greening.

The sulfur content of the tailings is 1.31 percent, which is reduced to SO₃3.275 percent, higher than the requirement (SO) of cement iron correction agent₃Less than 2.5%) and the sulfur content must be reduced. Therefore, by strengthening flotation, isobutyl xanthate with strong collecting force is added, the pH value of flotation is reduced, the recovery of sulfur is strengthened, and the sulfur content in tailings is reduced. The sulfur content in the fine fraction (-0.037 mm- +0.010 mm) tailings after concentration and filtration is stabilized below 1% (SO)₃Less than 2.5 percent) and meets the requirement of cement factories on the sulfur content of the cement iron correcting agent.

Preferably, the cyclone group in the step B is 4 cyclone groups with the model number of FX 350-PU.

Preferably, the water content of the slurry of the cyclone group in the step B is 60-65%, and the feeding pressure of the slurry entering the cyclone group is controlled to be 1.5kgf/m by adopting a variable frequency motor²Left and right.

Adopt above-mentioned technical scheme: for the coarse-grained tailings with the grain size of +0.037mm used for underground filling, the content of the coarse-grained tailings and the grain size of 0.037mm reaches more than 90 percent by improving the classification efficiency of the coarse-grained tailings and the grain size of 0.037mm of the cyclone group, so that the underground filling quantity and quality requirements are met;

fe in fine fraction-0.037 mm- +0.010mm tailings₂O₃The content of the iron in the tailings is 24.38 percent and is converted into Fe₂O₃34.83 percent, which is lower than the requirement of cement iron correcting agent (Fe)₂O₃Greater than 35%). In order to meet the requirement of a cement iron additive, the total iron content in tailings must be increased, and therefore, non-metal minerals such as coarse quartz and the like in tailings are recycled into coarse tailings by improving the coarse grading efficiency of a cyclone unit; the inclined plate thickener and the high-efficiency thickener are adopted to effectively remove the micro-fine clay so as to lead the Fe in the target particle size₂O₃Enriching; fe in tailings of fine fraction of-0.037 mm- +0.010mm after concentration and filtration₂O₃37.45 percent, and the cement iron correction agent SO for cement factories₃、Fe₂O₃The content requirement is that the water content of the filter cake after filtration is less than 10 percent. And the product is sold outside.

Preferably, the filter in the step D is a ceramic filter, and the water content of a filter cake is less than 10%.

Preferably, a flocculating agent is added into the sedimentation tank in the step E, and the adding amount of the flocculating agent is 20-30 g/t.

Preferably, in the step E, the water content of the micro-fine tailing after the flow through the concentrating and precipitating tank bottom is less than 20%, and the particle size is-0.01 mm.

In conclusion, the beneficial effects of the invention are as follows: according to the technical scheme of the full tailings grading and segmenting multi-way comprehensive utilization method, the coarse tailings with the size fraction of 0.037mm and the tailings in the tailings are used as filling sand for underground filling; fine-grained tailings with the grain size of-0.037 mm to-0.01 mm are used as an iron correcting agent in a cement plant, and the fine-grained tailings with the grain size of-0.01 mm and clay are transported to an earth and rockfill yard for greening through flocculation and precipitation, so that waste materials are changed into valuable materials, 100% of mine tailings are recycled, and the generated wastewater is completely returned to be used as production water. The method solves the problem of mine production tailing discharge, and also solves the problems of filling of an underground goaf and using sand and soil for open pit environmental treatment, ensures normal production of the mine, reduces yellow sand purchase amount, and increases extra income.

Drawings

FIG. 1 is a process flow diagram according to the present invention.

Detailed Description

The invention is further described with reference to the following figures and examples:

the first embodiment is as follows:

The technical scheme adopted by the invention is as follows:

1. improves the classification efficiency and content of coarse-grained tailings with the particle size of 0.037mm

Removing partial fine mud in tailings by adopting an inclined plate thickener, and grading the original two-section cyclone into a cyclone group: the model is 4 FX350-PU cyclone groups, and the feeding pressure of the cyclone groups is controlled to be 1.5kgf/m by adopting a variable frequency motor²The method has the advantages that the method is about, the mass concentration is 35-40%, the classification efficiency is improved by more than 10%, the content of +0.037mm in the settled sand of the cyclone group is more than or equal to 90%, the yield is improved by nearly 2%, 12 ten thousand tons of coarse fraction filling tailings are produced every year, and the requirements of entering and filling are met.

2. Increase Fe in tailings with the grain size of-0.037 mm- +0.01mm₂O₃Content of harmful element sulfur is reduced

The tailings contain Fe₂O₃Grade is 34.83%, SO₃3.275%, the iron content is low, the impurity sulfur content is high, and the total iron content must be increased and the sulfur content must be reduced to meet the requirement of the cement iron additive. The key technology for solving the problem is to improve iron and reduce sulfur and meet the requirement of the cement iron correction material. By improving the coarse grain grading efficiency of the cyclone group, the non-metal minerals such as coarse quartz and the like in the tailings are recycled into the coarse tailings, and the ultrafine clay is effectively removed by adopting an inclined plate thickener and a high-efficiency thickener, so that Fe in the target grade is Fe₂O₃And (4) enriching. In the sulfur flotation process, the adding amount of the isobutyl xanthate is 10-15 g/t, the pH value of flotation ore pulp is controlled to be 6.5-7.5, the recovery of sulfur is enhanced, and the sulfur content in tailings is reduced under the condition of double pipes. Fe in tailings of-0.037 mm- +0.01mm after concentration and filtration₂O₃Reaches 37.45 percent, is improved by 2.05 percent compared with the total tailings, and the sulfur of the tailings is stabilized below 1 percent (SO)₃Less than 2.5 percent) and meets the quality requirement of cement factories on iron correcting materials.

3. Research on solid-liquid separation technology of-0.037 mm- +0.01mm size fraction

The cement and iron correcting agent is required to have the water content of less than 10 percent, the key technology of the project solution, namely a 0.037mm- +0.01mm grain-grade tailing solid-liquid separation technology, divides the fine grain-grade concentration filtration treatment process into two sections of treatment, and the first section adopts a high-efficiency dense precipitator for concentration and precipitation to remove fine mud and water and improve the mass concentration of ore pulp by more than 60 percent; in the second stage, ceramic filtering technology is adopted for dehydration, a filter cake (with water content less than 10%) is used as an iron correction agent for a cement plant for external sales, and the generated filtrate is used as production return water.

4. Solid-liquid separation of-0.01 mm size fraction

The fine fraction tailings and clay automatically flow into a sedimentation tank, a flocculating agent is added for concentration and sedimentation to obtain fine mud (0.01 mm) with the water content of less than 20 percent, the fine mud is transported to an open pit to be used as mud for environmental control and soil discharge field greening, and the clear water of the fine fraction tailings and clay returns to the production water. And adding a flocculating agent into the sedimentation tank, wherein the adding amount of the flocculating agent is 20-30 g/t.

In conclusion, the pH value of the flotation is reduced during the sulfur flotation, and the isobutyl xanthate with strong collecting force is added, so that the recovery of sulfur is enhanced, and the reduction of sulfur contentThe sulfur content in the tailings meets the requirement of a cement plant on the sulfur content in the iron correcting agent; when the mass concentration of the underflow ore pulp of the inclined plate thickener reaches 35-40%, the underflow ore pulp enters a cyclone group for classification, and settled sand (+ 0.037 mm) of the cyclone group is used as an underground filling material and is conveyed to an underground filling vertical sand silo; b, overflowing the inclined plate densifier to remove Fe₂O₃Clay with low content of fine fraction (-0.01 mm), classifying coarse-grained non-metal minerals such as quartz in tailings into settled sand by the cyclone group in the step B, overflowing the cyclone group into a high-efficiency thickener in the step B to remove the fine clay, and making Fe in the target fraction₂O₃Enriching to meet the requirement of a cement plant on the iron content in the iron correcting material; when the mass concentration of the underflow ore pulp of the high-efficiency thickening precipitator is 60-65%, pumping the underflow ore pulp to a filter for filtering, taking an obtained filter cake as a cement and iron correction agent of a cement plant, removing clay with a micro-particle size of (-0.01 mm) from the overflow of the inclined plate thickener in the step B and removing Fe in the clay with a micro-particle size of (-0.01 mm) from the high-efficiency thickener in the step C₂O₃The content is 10 percent lower, the cyclone group in the step B grades coarse-grained non-metallic minerals such as quartz and the like in the tailings into settled sand, so that Fe in the tailings with fine fraction (-0.037 mm- +0.010 mm)₂O₃The enrichment is obtained, and the requirement of a cement plant on the iron content in the iron correction material is met.

Claims

1. The full tailings grading and segmenting multi-way comprehensive utilization method is characterized by comprising the following steps:

B. separation of coarse fraction +0.037mm tailings: pumping mineral dressing tailing pulp with the mass concentration of 15-20% into an inclined plate thickener for concentration, entering a cyclone group for classification when the mass concentration of underflow pulp of the inclined plate thickener reaches 35-40%, taking settled sand with the particle size of +0.037mm of the cyclone group as an underground filling material, and conveying the underground filling vertical sand silo;

C. the fine particle grade is improved to-0.037 mm- +0.01Fe in 0mm tailings₂O₃The content of (A): b, overflowing the inclined plate densifier to remove Fe₂O₃Grading low-content non-metal minerals such as clay with a fine particle size of-0.01 mm and coarse quartz into settled sand, overflowing the cyclone group in the step B into a high-efficiency thickener to remove the clay with fine particles, and making Fe in the target particle size₂O₃Enriching;

2. The full tailings fractionation multi-path comprehensive utilization method according to claim 1, characterized in that: and the cyclone group in the step B is 4 cyclone groups with the model number of FX 350-PU.

3. The full tailings fractionation multi-path comprehensive utilization method according to claim 1 or 2, characterized in that: the water content of the slurry entering the cyclone group in the step B is 60-65%, and the feeding pressure of the slurry entering the cyclone group is controlled to be 1.5kgf/m by adopting a variable frequency motor²Left and right.

4. The full tailings fractionation multi-path comprehensive utilization method according to claim 1, characterized in that: and D, the filter is a ceramic filter, and the water content of a filter cake is less than 10%.

5. The full tailings fractionation multi-path comprehensive utilization method according to claim 1, characterized in that: and D, adding a flocculating agent into the sedimentation tank in the step E, wherein the adding amount of the flocculating agent is 20-30 g/t.

6. The full tailings fractionation multi-path comprehensive utilization method according to claim 1, characterized in that: and E, concentrating and precipitating the bottom flow of the precipitation tank in the step E to obtain the micro-fine grain tailings with the water content of less than 20 percent and the grain diameter of-0.01 mm.