CN108979713A - A kind of processing of tailing and placement method - Google Patents

Abstract

The invention discloses a tailings processing and filling method, which belongs to the field of utilization and disposal of tailings. The method is as follows: classify the tailings slurry to obtain fine-grained tailings slurry and coarse-grained tailings slurry; dewater separately according to the application, fine-grained tailings slurry to obtain fine-grained tailings, and coarse-grained tailings to obtain fine aggregate, granulation, and mortar Coarse tailings for dry-mixed mortar and coarse-grained tailings; fine-grained tailings are sintered at high temperature, and cementitious materials are added to the coarse-grained tailings for granulation, mortar, and dry-mixed mortar to prepare coarse aggregate and mortar respectively. Materials and dry-mixed mortar materials; mix coarse aggregate and fine aggregates and transport them downhole through filling wells, transport mortar materials downhole through filling pipes, and fill after mixing; transport dry-mixed mortar materials downholes and mix them with flushing water Prepare dry-mix mortar material mixture, mix with aggregate and fill. The method can shorten the treatment and hardening time of the filling material, enhance the strength of the filling body, improve the downhole operation conditions and reduce the pollution of the underground environment.

Description

A tailings processing and filling method

technical field

The invention belongs to the technical field of utilization and disposal of tailings, and in particular relates to a treatment and filling method of tailings.

Background technique

With the development of the economy, the society's demand for mineral products has increased significantly, and the grade of available mineral products has gradually decreased. The scale of mineral development has increased accordingly, and the amount of tailings produced has continued to increase. Problems such as tailings stockpiling occupy a large area, serious environmental pollution, and many safety hazards have become increasingly prominent. The comprehensive utilization of tailings is the fundamental method to solve the above problems. The utilization methods mainly include recovery of valuable components, production of building materials, tailings filling, etc. Among them, filling goafs with tailings is an effective way to utilize tailings in large quantities , It is not only a fundamental solution to solve the environmental pollution problem of tailings ponds and eliminate potential safety hazards of tailings ponds, but also helps to reduce mining costs, improve mining safety and comprehensive utilization of resources, and reduce surface subsidence and land occupation. Tailings filling can be divided into cemented filling and non-cemented filling. Non-cemented filling is to transport the tailings to the goaf by hydraulic or wind power through pipelines; cemented filling is to mix the tailings with an appropriate amount of cementitious material and water to form a high-concentration slurry or paste, and transport it to the goaf through pipelines Filling to form a filling body with certain strength and integrity. Although the cost of cemented filling is higher than that of non-cemented filling, it is the main method of tailings filling because it has good maintenance effect of surrounding rock, low ore dilution rate, and can effectively improve mining safety.

The inherent contradiction of cemented filling is the contradiction between the strength of the formed filling body and the fluidity of the filling material pipeline. In order to ensure the fluidity of the filling material, the mass concentration of solid materials in the filling material generally does not exceed 70%. If the mass concentration continues to increase, self-flowing will be difficult, and pumping is required, which will further increase the cost. However, under the condition of 70% mass concentration, the volume concentration of solid material is actually only 45% to 50%, and more than half of the volume of the filling material is occupied by water. The reaction will consume part of the water, and the remaining unconsumed part will remain inside the filling body to form pores, thereby reducing the strength of the filling body. Increasing the mass concentration of solids in the filling material can increase the final strength of the filling body, but there is a limit to the increase of the mass concentration. This limit is that it cannot exceed the fluidity requirements of fluid transportation, otherwise it will not flow smoothly in the pipeline and cannot be transported. down the well. The fluidity of the filling material is high, and some water will be secreted and fine particles will be precipitated on the surface after filling to the stope. Therefore, stricter filling and isolation measures are required. The construction volume is large, the hardening speed of the filling body is slow, and the surface of the filling body needs to be It takes a long time to load, which seriously affects the mining efficiency. In order to improve the strength of the filling body under the premise of ensuring the fluidity of the filling material, the only way to increase the cost is to increase the content of the gelling material. In addition, the construction cost of the cemented filling system is high, and it is difficult to deal with pipeline blockage. Once the pipe is blocked, it will have a great impact on production and safety. After each filling, the pipeline needs to be strictly cleaned, and a large amount of flushing water and mixed mud and sand need to be collected and pumped by special facilities, which deteriorates the downhole operating environment. Therefore, it is of great significance to study tailings underground filling methods with good filling quality, safety, economy and convenience.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art, to provide a tailings treatment and filling method, which can shorten the treatment and hardening time of the filling material, enhance the strength of the filling body, improve the underground working conditions, and reduce the damage to the underground environment. Pollution.

To achieve the above object, the present invention adopts the following technical solutions:

A treatment and filling method for tailings of the present invention comprises the following steps:

Step 1: Grading

Classifying the tailings slurry to obtain fine-grained tailings slurry and coarse-grained tailings slurry, wherein the solid mass of the classified fine-grained tailings slurry accounts for 5% to 25% of the total solid mass of the original tailings slurry;

Step 2: Dehydration

Dewatering the graded tailings slurry can be divided into:

(1) After dehydrating the fine-grained tailings slurry, fine-grained tailings are obtained, and the moisture content of the fine-grained tailings is 5% to 30%;

(2) Divide the coarse tailings slurry into four parts according to the usage:

The first part accounts for 5% to 20% of the mass of the total coarse-grained tailings slurry. After the coarse-grained tailings slurry is dehydrated, the pollutants are initially removed to obtain fine aggregates. The moisture content of the fine aggregates is 5%. ~15%;

The second part accounts for 40% to 65% of the mass of the total coarse-grained tailings slurry, and initially removes pollutants to obtain coarse-grained tailings for granulation. The moisture content of the coarse-grained tailings for granulation is 10%. ~25%;

The third part accounts for 20% to 40% of the mass of the total coarse-grained tailings slurry. After the coarse-grained tailings slurry is dehydrated, the pollutants are initially removed to obtain coarse-grained tailings for mortar. The coarse-grained tailings for mortar is The moisture content is 30% to 50%;

The fourth part accounts for 1% to 5% of the mass of the total coarse-grained tailings slurry, which means that after the coarse-grained tailings slurry is dehydrated, the pollutants in the coarse-grained tailings are removed or harmlessly removed to obtain coarse particles for dry-mixed mortar. Tailings, the moisture content of the coarse-grained tailings for dry-mixed mortar is ≤3%;

Step 3: Treat tailings

According to the type of tailings after dewatering, they are treated separately:

The first method: treatment of fine particle tailings

The fine-grained tailings are mixed with other materials and then sintered at high temperature to be used as building materials, specifically for the production of sintered products or as ingredients for firing cement;

The second method: treatment of coarse tailings for granulation

1) Deeply remove or detoxify the pollutants in the coarse tailings for granulation, and then carry out subsequent treatment;

2) Add cementitious material to the coarse tailings for granulation, and mix evenly to obtain the gelled mixture of coarse tailings for granulation; wherein, according to the solid mass ratio, the coarse tailings for granulation: cementitious material = (19～3): 1;

3) Compressing or extruding the coarse-grained tailings cementitious mixture for granulation to obtain spherical, ellipsoidal or short strip-shaped particles;

4) Curing spherical, ellipsoidal or short strip-shaped particles to obtain coarse aggregate; wherein, the strength of the coarse aggregate is 1-10 MPa;

The third method: processing coarse tailings for mortar

1) Deeply remove or harmlessly remove the pollutants in the coarse-grained tailings for mortar, and then carry out subsequent treatment;

2) Add cementitious material to the coarse-grained tailings for mortar, and mix evenly to obtain a mortar material; wherein, according to the solid mass ratio, the coarse-grained tailings for mortar: cementitious material=(15～2):1, mortar material The slump ≥ 160mm;

The fourth type: treatment of coarse-grained tailings for dry-mixed mortar

Add cementitious material to the coarse-grained tailings for dry-mixed mortar, and mix evenly to obtain a dry-mixed mortar material; wherein, according to the solid mass ratio, coarse-grained tailings for dry-mixed mortar: cementitious material=(15～2): 1;

Step 4: Filling

Set filling wells and filling pipes in the goaf to be filled, transport the filling aggregate and mortar materials to the underground through the filling wells and filling pipes respectively, and fill after mixing, specifically:

(1) mix the coarse aggregate prepared in step 3 and the fine aggregate prepared in step 2 evenly to obtain the filling aggregate, and deliver the filling aggregate to the downhole through the filling well;

(2) Transport the mortar material downhole through the filling pipe;

(3) After the filling aggregate and mortar materials are mixed evenly underground, they are filled to the goaf underground to form a filling body;

(4) After the filling pipe is filled each time, the filling pipe is rinsed with water, and the flushing water generated is stored for later use; the dry-mixed mortar material is prepared on the ground and transported to the underground, and the flushing water is mixed with the dry-mixed mortar material to obtain the mortar material The mixture; the mortar material mixture is mixed with the filling aggregate, and filled into the underground goaf to form a filling body; wherein, the strength of the filling body after hardening is 2-15 MPa.

In the above step 2, after dehydration of the graded tailings slurry, the obtained water is recycled as production water or discharged up to the standard after being treated; wherein, the treatment method of the dehydrated water is to remove the components in the water that affect production or the water other pollutants.

In the step 2, the dehydration is one or more combination of gravity dehydration, mechanical dehydration or thermal energy dehydration.

In step 2, for the coarse tailings for granulation and the coarse tailings for mortar, dehydration is used to reduce the water content of the tailings on the one hand, and in addition, it is necessary to retain the water required for the hydration reaction after the ingredients and during the curing process. lost moisture.

In the step 3, during the processing of the fine tailings, the sintered product is one or more of sintered bricks, sintered tiles, ceramsite, pottery or porcelain.

In the step 3, in the process of processing coarse tailings for granulation, the cementitious material is one of cement, cement clinker, lime, extralime, gypsum, desulfurized gypsum or water glass. A mixture of one or more kinds, when it is a mixture, the mixing ratio is any ratio.

In the step 3, in the process of processing the coarse tailings for granulation, the maintenance method is conventional heat preservation and moisture retention or standing under pressure and steam under sealed conditions, and the curing time is 1-20 hours. 14d.

In step 3, during the process of treating the coarse-grained tailings for granulation, the particle size of the obtained coarse aggregate is 2-60mm, and the pollutant content of the coarse aggregate is lower than the requirements of relevant standards or norms.

In the step 3, during the process of processing the coarse tailings for granulation, auxiliary materials are added when the coarse tailings for granulation are mixed with the cementitious material, and the added mass of the auxiliary materials is the coarser tailings for granulation. 0-20% of the total solid mass of the mixture of granular tailings and cementitious material;

The auxiliary material is one or a mixture of pozzolanic active materials or admixtures;

The material with pozzolanic activity is one or more of fly ash, furnace bottom ash, metal smelter ash, spontaneous combustion coal gangue, red mud or pozzolan; or has the ability to improve grading conditions, increase Easy-going material.

The admixture is an admixture with functions of water reduction, quick setting, early strength, antifreeze and expansion.

In step 3, during the process of treating the mortar with coarse tailings, when the slump of the mortar material does not meet the requirements, water is added to the mortar material and mixed evenly for adjustment.

In the step 3, in the process of treating the mortar with coarse tailings, the cementitious material is one of cement, cement clinker, lime, extralime, gypsum, desulfurized gypsum or water glass Or several mixtures, when it is a mixture, the mixing ratio is any ratio.

In the step 3, during the process of processing the coarse tailings for mortar, auxiliary materials are added when the coarse tailings for mortar are mixed with the cementitious material, and the added mass of the auxiliary materials is the coarse tailings for mortar. 0-20% of the total solid mass of the mixture of ore and cementitious material;

The auxiliary material is one or a mixture of pozzolanic active materials or admixtures;

The material with pozzolanic activity is one or more of fly ash, furnace bottom ash, metal smelter ash, spontaneous combustion coal gangue, red mud or pozzolan; it has the ability to improve grading conditions, increase The role of ease.

The admixture is an admixture with functions of water reduction, quick setting, early strength, antifreeze and expansion.

In the step 3, during the process of treating the mortar with coarse-grained tailings, the pollutant content of the mortar material is lower than the requirements of relevant standards and normative limit values.

In the step 3, in the process of treating the dry-mixed mortar with coarse tailings, the cementitious material is cement, cement clinker, lime, extralime, gypsum, desulfurized gypsum or water glass One or more mixtures, when it is a mixture, the mixing ratio is any ratio.

In the step 3, during the process of treating the coarse-grained tailings for the dry-mixed mortar, auxiliary materials are added when the coarse-grained tailings for the dry-mixed mortar are mixed with the cementitious material, and the added mass of the auxiliary materials is dry 0% to 20% of the total solid mass of the mixture of coarse tailings and cementitious material for mortar mixing;

The auxiliary material is one or a mixture of pozzolanic active materials or admixtures;

The material with pozzolanic activity is one or more of fly ash, furnace bottom ash, metal smelter ash, spontaneous combustion coal gangue, red mud or pozzolan; it has the ability to improve grading conditions, increase The role of ease.

The admixture is an admixture with functions of water reduction, quick setting, early strength, antifreeze and expansion.

In step 3, during the process of treating the dry-mixed mortar with coarse-grained tailings, the pollutant content of the dry-mixed mortar material is lower than the requirements of relevant standards and normative limit values.

In the step 4, the percentage of the fine aggregate to the total mass of the aggregate is 10%-30%.

In the step 4, the mixing of the aggregates can also be sending the coarse aggregates and the fine aggregates downhole at the same time, and the mixing is completed during the falling and transporting process.

In said step 4, in the mixing of aggregates, materials that improve workability, improve aggregate gradation conditions and protect the integrity of coarse aggregates can also be delivered at the same time; said improved workability, improved aggregate The material for grading conditions and protecting the integrity of coarse aggregate is one of fly ash, furnace bottom ash or crushed spontaneous combustion coal gangue.

A kind of treatment and filling method of tailings of the present invention, compared with prior art, its beneficial effect is:

(1) The tailings treatment and filling method of the present invention can enhance the strength of the underground filling body or reduce the amount of cementitious material under the same strength requirements, solve the problem of the source of the filling material aggregate, and reduce the moisture content of the filling material Thereby improving the underground working environment, reducing the risk and intensity of underground environmental pollution, and reducing the discharge of tailings;

(2) The tailings treatment and filling method of the present invention classifies the tailings slurry, and the fine particle tailings produced after classification are used for the production of sintered building materials, the smaller particle size saves the crushing cost of raw materials, and the quality of sintered products is improved . The content of pollutants in fine particle tailings is relatively high, and most of them are removed after high-temperature sintering;

(3) The tailings treatment and filling method of the present invention. The coarse tailings produced after classification are used for underground filling. The specific surface area of the coarse tailings is small, which helps to combine with the cementitious material to form a higher strength. The content of pollutants in the coarse particle tailings is less, and the larger particles are good for dehydration, which is helpful for the removal of pollutants;

(4) The treatment and filling method of tailings of the present invention have a flexible and adjustable tailings treatment ratio, and the dehydration index of fine-grained tailings can be adjusted according to different utilization modes, and the dehydration index of coarse-grained tailings can be adjusted according to the use of fine aggregates. , Adjust the material ratio and performance requirements for granulation, mortar and dry-mixed mortar;

(5) In the treatment and filling method of tailings of the present invention, the coarse aggregate is well-graded spherical, ellipsoidal or short strip-shaped particles, and its benefit is that particles of different particle sizes can be piled up and filled with each other, but Newly introduced particles tend to break up during filling, resulting in less strong chips. In this application, fine aggregate and coarse aggregate are delivered at the same time. The fine aggregate can protect and buffer the integrity of the coarse aggregate. The overall grading condition of the aggregate is improved.

(6) According to the tailings treatment and filling method of the present invention, the aggregate and the mortar material are delivered separately. The moisture content of the mortar material is relatively high, which can meet the requirements of conveying fluidity, and the moisture content of the aggregate is relatively low. After the mortar material and aggregate are fully mixed, part of the water migrates from the mortar material to the aggregate, and the moisture content of the mortar material decreases, which helps to improve the strength, while the fluidity decreases, the quality of the filling body is good, and the downhole operating environment is improved. The moisture content of the aggregate increases, and the moisture required for the continuous hydration reaction of the coarse aggregate is guaranteed;

(7) The treatment and filling method of tailings of the present invention flushes the pipe flushing water produced by the filling pipe and is used after being mixed with the dry-mixed mortar material, which improves the underground working environment;

(8) The strength requirement of the tailings processing and filling method of the present invention is less than that of general building materials, so the additional materials can be a large number of low-quality materials or even general industrial solid waste, and each process index is within the existing technical conditions. Both are easy to achieve and can meet the requirements of economy.

Description of drawings

Fig. 1 is a process flow diagram of the tailings treatment and filling method of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with embodiment.

Example 1

A kind of processing and filling method of tailings, its process flow diagram as shown in Figure 1, comprises the following steps:

Step 1: Grading

The tailings slurry is classified by a cyclone, and the underflow tailings slurry of the cyclone is further classified by a high-frequency vibrating screen. The coarse tailings slurry is on the screen, and the fine tailings slurry is obtained by mixing the slurry under the screen and the overflow of the cyclone. The solid mass in fine particle tailings slurry after classification accounts for 15% of the total solid mass of the original tailings slurry;

Step 2: Dehydration

The dehydration of the graded tailings is specifically divided into:

(1) Dewatering the fine particle tailings slurry using a plate and frame filter press to obtain fine particle tailings, the moisture content of the fine particle tailings is 15%;

(2) After dehydrating the 10% coarse particle tailings slurry using a diaphragm filter press, fine aggregate is obtained, and the moisture content of the fine aggregate is 10%;

(3) After dehydrating 60% of the coarse-grained tailings slurry using a plate-and-frame filter press, obtain coarse-grained tailings for granulation, and the moisture content of the coarse-grained tailings for granulation is 25%;

(4) After thickening the 28% coarse-grained tailings slurry with a thickener, the coarse-grained tailings for mortar are obtained, and the moisture content of the coarse-grained tailings for mortar is 45%;

(5) After dehydrating the remaining coarse-grained tailings slurry using a disc vacuum filter, remove or harmlessly remove the pollutants in the coarse-grained tailings to obtain coarse-grained tailings for dry-blended mortar. The dry-blended The moisture content of coarse tailings for mortar is 3%;

The water obtained from tailings slurry dehydration is treated and reused as production water.

Step 3, tailings are processed, the method steps are as follows:

(1) Fine particle tailings are used to produce sintered bricks;

(2) Both the coarse tailings for granulation and the coarse tailings for mortar are removed or the pollutants in the coarse tailings are harmlessly treated, and then subsequent treatment is carried out;

(3) Ordinary Portland cement is added to the coarse tailings for granulation. The ratio of the two is based on the solid mass. Coarse tailings for granulation: ordinary Portland cement = 19:1. 10% by mass of fly ash is mixed evenly to obtain a mixture, and then the mixture is pressed into oblate spherical particles with good gradation and a particle size of 2 to 50 mm;

(4) Curing the oblate spherical particles for 3 days in a plastic greenhouse to obtain coarse aggregate. The strength of the coarse aggregate is 1.5MPa, and the pollutant content of the coarse aggregate is lower than the relevant standards and specification limits;

(5) Ordinary Portland cement is added to the coarse tailings for mortar, the ratio of the two is based on the solid mass, coarse tailings for mortar: cement = 15:1, and coarse tailings and cement for granulation are added The fly ash with 10% of the total mass of the coagulation material is mixed with water to obtain a mortar material. The pollutant content of the mortar material is lower than the relevant standards and specification limit requirements, and the slump of the mortar material is 200mm.

(6) Ordinary Portland cement is added to the coarse-grained tailings for dry-mixed mortar, and the two are based on the solid mass ratio, coarse-grained tailings for dry-mixed mortar: cement = 12:1; after mixing evenly, dry-mixed mortar is obtained materials, the pollutant content of dry-mixed mortar materials is lower than the requirements of relevant standards and normative limit values.

Step 3: After mixing the coarse aggregate and fine aggregate, the filling aggregate is obtained, transported to the underground through the filling well, and the mortar material is transported to the underground through the wear-resistant filling pipe by gravity, and the filling aggregate and the mortar material are mixed evenly before filling To the mined-out area underground, a filling body is formed, and a small amount of flushing water generated by flushing the filling pipe is mixed with the dry-mixed mortar material, and the mortar material mixture obtained is mixed with the filling aggregate to fill the goaf to form a filling body. The strength of the filling body after hardening is 2.5MPa, and the integrity is good.

Example 2

A kind of processing and filling method of tailings, its process flow diagram as shown in Figure 1, comprises the following steps:

Step 1: Grading

Use a cyclone to classify the tailings slurry. The underflow of the cyclone obtains coarse tailings slurry, and the overflow of the cyclone obtains fine particle tailings slurry. After classification, the solid mass in the fine particle tailings slurry accounts for 10% of the total solid mass of the original tailings slurry;

Step 2: Dehydration

The dehydration of the graded tailings is specifically divided into:

(1) Dewatering the fine particle tailings slurry using a belt filter press to obtain fine particle tailings, the moisture content of the fine particle tailings is 15%;

(2) Dewatering the coarse tailings slurry using a box-type filter press to obtain coarse tailings, the moisture content of the coarse tailings is 22%;

a) air-drying 20% of coarse-grained tailings to obtain fine aggregate, and the moisture content of the fine aggregate is 10%;

b) 40% of the coarse-grained tailings are used as coarse-grained tailings for granulation;

c) 35% of the coarse-grained tailings are used as coarse-grained tailings for mortar;

d) drying and dehydrating 5% of the coarse-grained tailings, deeply removing or harmlessly decontaminating the pollutants in the coarse-grained tailings, and obtaining coarse-grained tailings for dry-mixed mortar, and the coarse-grained tailings for dry-mixed mortar The moisture content of the mine is 2%;

The water obtained from tailings slurry dehydration is treated and reused as production water.

Step 3, the water-containing tailings are processed, and the method steps are as follows:

(1) Fine particle tailings are used to produce ceramsite;

(2) Both the coarse tailings for granulation and the coarse tailings for mortar are removed or the pollutants in the coarse tailings are harmlessly treated, and then subsequent treatment is carried out;

(3) Add cement clinker powder and desulfurized gypsum powder to the coarse tailings for granulation, and the proportion of the three is based on the solid mass, coarse tailings for granulation: cement clinker powder: desulfurized gypsum powder = 19:1 : 1, in addition, add 5% of the total mass of the three fly ash to mix uniformly to obtain a mixture, and then press the mixture into spherical particles with good gradation and a particle size of 2 to 50 mm;

(4) Curing the spherical particles by high-temperature steam for 1d in a closed chamber to obtain coarse aggregate. The strength of the coarse aggregate is 1.5MPa, and the pollutant content of the coarse aggregate is lower than the relevant standards and specification limits;

(5) Add ordinary Portland cement to the coarse tailings for mortar, the ratio of the two is based on the solid mass, coarse tailings for mortar: cement = 15:1, and add a crushing furnace with 10% of the total mass of the two Bottom ash and 1% calcium lignosulfonate are mixed evenly after adding water to obtain a mortar material. The pollutant content of the mortar material is lower than the relevant standards and specification limit requirements, and the slump of the mortar material is 220mm.

(6) Add extra-grade lime and cement clinker to the coarse-grained tailings for dry-mixed mortar, and the three are based on the solid mass ratio, coarse-grained tailings for dry-mixed mortar: desulfurized gypsum powder: cement clinker = 6:2: 1; After mixing evenly, dry-mixed mortar material is obtained, and in addition, 5% of the total mass of the three spontaneous combustion coal gangue and 5% red mud are added, and after adding water, mix uniformly to obtain a mortar material mixture, and the pollutant content of the mortar material mixture is lower than Relevant standards and normative limit value requirements.

Step 3, put the coarse aggregate and fine aggregate into the underground in proportion to the feeding well, transport the mortar material to the underground through the wear-resistant filling pipe, mix the filling aggregate and the mortar material evenly, and then fill it into the goaf in the underground. Form a filling. After a small amount of flushing water produced by flushing the filling pipe is mixed with the dry-mixed mortar material, the mortar material mixture obtained is mixed with the filling aggregate and filled into the goaf to form a filling body. The strength of the filling body after hardening is 2 MPa, and the integrity is good.

Example 3

A kind of processing and filling method of tailings, its process flow diagram as shown in Figure 1, comprises the following steps:

Step 1: Grading

Use a cyclone to classify the tailings slurry. The underflow of the cyclone obtains coarse tailings slurry, and the overflow of the cyclone obtains fine particle tailings slurry. After classification, the solid mass in the fine particle tailings slurry accounts for 15% of the total solid mass of the original tailings slurry;

Step 2: Dehydration

The dehydration of the graded tailings is specifically divided into:

(1) Obtain fine particle tailings after using a diaphragm filter press to dehydrate the fine particle tailings slurry, and the moisture content of the fine particle tailings is 10%;

(2) Dehydrating the coarse tailings slurry using a plate and frame filter press to obtain coarse tailings, the moisture content of the coarse tailings is 20%;

a) Air-dry the 15% coarse tailings to obtain fine aggregate, and the moisture content of the fine aggregate is 15%;

b) 64% of the coarse-grained tailings are used as coarse-grained tailings for granulation;

c) 20% of the coarse-grained tailings are used as coarse-grained tailings for mortar;

d) further dehydrating the 1% coarse-grained tailings to obtain coarse-grained tailings for dry-mixed mortar, and the moisture content of the coarse-grained tailings for dry-mixed mortar is 3%;

The water obtained from tailings slurry dehydration is treated and reused as production water.

Step 3, the water-containing tailings are processed, and the method steps are as follows:

(1) Batching for firing cement after drying the fine particle tailings;

(2) Both the coarse tailings for granulation and the coarse tailings for mortar are removed or the pollutants in the coarse tailings are harmlessly treated, and then subsequent treatment is carried out;

(3) Add cement clinker powder and desulfurized gypsum powder to the coarse tailings for granulation, the three are proportioned according to the solid mass, coarse tailings for granulation: cement clinker powder, slaked lime powder: gypsum powder=20 : 1:0.5:1, in addition, add 4% of the total mass of the three fly ash to mix evenly to obtain a mixture, and then press the mixture into oblate spherical particles with good gradation and a particle size of 2-50mm;

(4) Transport the oblate spheroidal particles to the room, and keep the room moist for 7 days to obtain coarse aggregate. The strength of the coarse aggregate is 2MPa, and the pollutant content of the coarse aggregate is lower than the requirements of relevant standards and specification limits;

(5) Add fly ash Portland cement to the coarse tailings for mortar, the ratio of the two is based on the solid mass, coarse tailings for mortar: cement = 15:1, and add 5% of the total mass of the two Crushing furnace bottom ash, adding water and mixing evenly to obtain mortar material, the pollutant content of the mortar material is lower than the requirements of relevant standards and specification limits, and the slump of the mortar material is 180mm.

In step 3, the coarse aggregate and the fine aggregate are simultaneously dropped into the well in proportion through the feeding well, and 5% of the total mass of the two is added with fly ash at the same time. The mortar material is pumped downhole through the wear-resistant filling pipe, the aggregate and mortar material are evenly mixed and then filled into the underground goaf to form a filling body, and a small amount of flushing water generated by flushing the filling pipe is mixed with the dry-mixed mortar material. The obtained mortar material mixture is mixed with the filling aggregate and filled into the goaf to form a filling body. The strength of the filling body after hardening is 2.5MPa, and the integrity is good.

The above is only the best embodiment of the present invention, and is not intended to limit the present invention in any form. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, can use the method content disclosed above to analyze the present invention. Many possible changes and modifications in the technical solution of the invention belong to the protection scope of the claims.

Claims (10)

1. A treatment and filling method for tailings, characterized in that, comprising the following steps: Step 1: Grading Classifying the tailings slurry to obtain fine-grained tailings slurry and coarse-grained tailings slurry, wherein the solid mass in the classified fine-grained tailings slurry accounts for 5% to 25% of the total solid mass of the original tailings slurry; Step 2: Dehydration Dewatering the graded tailings slurry can be divided into: (1) After dehydrating the fine-grained tailings slurry, fine-grained tailings are obtained, and the moisture content of the fine-grained tailings is 5% to 30%; (2) Divide the coarse tailings slurry into four parts according to the usage: The first part accounts for 5% to 20% of the mass of the total coarse-grained tailings slurry. After the coarse-grained tailings slurry is dehydrated, the pollutants are initially removed to obtain fine aggregates. The moisture content of the fine aggregates is 5%. ~15%; The second part accounts for 40% to 65% of the mass of the total coarse-grained tailings slurry. After the coarse-grained tailings slurry is dehydrated, pollutants are initially removed to obtain coarse-grained tailings for granulation. The coarse-grained tailings for granulation are The moisture content of the tailings is 10% to 25%; The third part accounts for 20% to 40% of the mass of the total coarse-grained tailings slurry. After the coarse-grained tailings slurry is dehydrated, the pollutants are initially removed to obtain coarse-grained tailings for mortar. The coarse-grained tailings for mortar is The moisture content is 30% to 50%; The fourth part accounts for 1% to 5% of the mass of the total coarse-grained tailings slurry, which means that after the coarse-grained tailings slurry is dehydrated, the pollutants in the coarse-grained tailings are removed or harmlessly removed to obtain coarse particles for dry-mixed mortar. Tailings, the moisture content of the coarse-grained tailings for dry-mixed mortar is ≤3%; Step 3: Treat tailings According to the type of tailings after dewatering, they are treated separately: The first method: treatment of fine particle tailings The fine-grained tailings are mixed with other materials and then sintered at high temperature to be used as building materials, specifically for the production of sintered products or as ingredients for firing cement; The second method: treatment of coarse tailings for granulation 1) Deeply remove or detoxify the pollutants in the coarse tailings for granulation, and then carry out subsequent treatment; 2) Add cementitious material to the coarse tailings for granulation, and mix evenly to obtain the gelled mixture of coarse tailings for granulation; wherein, according to the solid mass ratio, the coarse tailings for granulation: cementitious material = (19～3): 1; 3) Compressing or extruding the coarse-grained tailings cementitious mixture for granulation to obtain spherical, ellipsoidal or short strip-shaped particles; 4) Curing spherical, ellipsoidal or short strip-shaped particles to obtain coarse aggregate; wherein, the strength of the coarse aggregate is 1-10 MPa; The third method: processing coarse tailings for mortar 1) Deeply remove or harmlessly remove the pollutants in the coarse-grained tailings for mortar, and then carry out subsequent treatment; 2) Add cementitious material to the coarse-grained tailings for mortar, and mix evenly to obtain a mortar material; wherein, according to the solid mass ratio, the coarse-grained tailings for mortar: cementitious material=(15～2):1, mortar material The slump ≥ 160mm; The fourth type: treatment of coarse-grained tailings for dry-mixed mortar Add cementitious material to the coarse-grained tailings for dry-mixed mortar, and mix evenly to obtain a dry-mixed mortar material; wherein, according to the solid mass ratio, coarse-grained tailings for dry-mixed mortar: cementitious material=(15～2): 1; Step 4: Filling Set filling wells and filling pipes in the goaf to be filled, transport the filling aggregate and mortar materials to the underground through the filling wells and filling pipes, and fill them after mixing, specifically: (1) mix the coarse aggregate prepared in step 3 and the fine aggregate prepared in step 2 evenly to obtain the filling aggregate, and deliver the filling aggregate to the downhole through the filling well; (2) Transport the mortar material downhole through the filling pipe; (3) After the filling aggregate and mortar materials are mixed evenly underground, they are filled to the goaf underground to form a filling body; (4) After the filling pipe is filled each time, the filling pipe is rinsed with water, and the flushing water generated is stored for later use; the dry-mixed mortar material is prepared on the ground and transported to the underground, and the flushing water is mixed with the dry-mixed mortar material to obtain the mortar material The mixture; the mortar material mixture is mixed with the filling aggregate, and filled into the underground goaf to form a filling body; wherein, the strength of the filling body after hardening is 2-15 MPa. 2. The tailings treatment and filling method according to claim 1, characterized in that, in the step 2, the dehydration is one or more combinations of gravity dehydration, mechanical dehydration or thermal energy dehydration. 3. The treatment and filling method of tailings as claimed in claim 1, characterized in that, in the step 3, in the process of processing fine tailings, the sintered products are sintered bricks and sintered tiles One or more of ceramsite, pottery or porcelain. 4. The processing and filling method of tailings as claimed in claim 1, characterized in that, in said step 3, said cementitious material is cement, cement clinker, lime, extralime, gypsum, desulfurization A mixture of one or more of gypsum or water glass, when it is a mixture, the mixing ratio is any ratio. 5. The processing and filling method of tailings as claimed in claim 1, characterized in that, in the step 3, in the process of processing coarse tailings for granulation, the maintenance method is conventional heat preservation Stand still with moisture or under pressure and steam under sealed conditions, the curing time is 1-14 days; the particle size of the obtained coarse aggregate is 2-60mm, and the pollutant content of the coarse aggregate is lower than the relevant standards or specification limits . 6. The processing and filling method of tailings as claimed in claim 1, characterized in that, in the step 3, auxiliary materials are added when the coarse tailings are mixed with the cementitious material, and the added mass of the auxiliary materials is 0-20% of the total solid mass of the mixture of coarse tailings and cementitious material for granulation. 7. The treatment and filling method of tailings as claimed in claim 6, characterized in that, the auxiliary material is a mixture of one or both of materials with pozzolanic activity or admixtures; The material with pozzolanic activity is one or more of fly ash, furnace bottom ash, metal smelter ash, spontaneous combustion coal gangue, red mud or pozzolan; or has the ability to improve grading conditions, increase Workable materials; The admixture is an admixture with functions of water reduction, quick setting, early strength, antifreeze and expansion. 8. The tailings treatment and filling method according to claim 1, characterized in that, in the step 4, the percentage of the fine aggregate in the total mass of the aggregate is 10%-30%. 9. The processing and filling method of tailings as claimed in claim 1, characterized in that, in the step 4, the mixing of the aggregate is to deliver the coarse aggregate and the fine aggregate to the underground simultaneously, and after falling and Blending is done during shipping. 10. The treatment and filling method of tailings as claimed in claim 1, characterized in that, in the step 4, during the mixing of aggregates, delivery is made simultaneously to improve workability, improve aggregate grading conditions and protect Coarse aggregate integrity material.