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CN-122010513-A - Composite filling mortar of steel slag sand fine tailings and preparation and use methods thereof

CN122010513ACN 122010513 ACN122010513 ACN 122010513ACN-122010513-A

Abstract

The invention discloses steel slag sand fine tailings composite filling mortar and a preparation and use method thereof, and belongs to the technical field of tailings cemented filling materials. The mortar raw material comprises fine tailings, steel slag sand, a magnetic volcanic ash cementing material, a gel breaker and an ultrafine particle catcher, wherein the magnetic volcanic ash cementing material comprises magnetic powder particles, the residual magnetic induction intensity of the magnetic powder particles is 0.15-2.5 mM, and the mass of the magnetic volcanic ash cementing material accounts for 5-10% of the total amount of the magnetic volcanic ash cementing material. By adopting the magnetic volcanic ash cementing material, the magnetic aggregation and magnetism effects of the magnetic volcanic ash cementing material and the fine and weak magnetic particles in the tailings can be utilized to drive other particles to approach the steel slag sand together and form an aggregate, so that uneven strength distribution of the consolidated body caused by different gravity sedimentation speeds of the fine sand and the fine tailings is avoided, and the consumption and filling cost of the cementing material can be reduced while the strength of the filling body is obviously improved.

Inventors

  • FAN LUQIAN

Assignees

  • 樊鲁倩

Dates

Publication Date
20260512
Application Date
20260303

Claims (10)

  1. 1. The steel slag sand fine tailings composite filling mortar is characterized in that the mortar raw materials comprise fine tailings, steel slag sand, magnetic volcanic ash cementing material, a gel breaker and an ultrafine particle catcher, wherein: at least 90% of the tailings particles in the fine tailings can pass through a 200-mesh sieve, and the D50 of the tailings particles is less than or equal to 20 microns; The granularity range of the steel slag sand is 0.1-1 mm; The material composition of the magnetic volcanic ash cementing material comprises volcanic ash components, an exciting agent and magnetic powder particles, wherein the mass ratio of the magnetic volcanic ash cementing material to the absolute dry tailings in the fine tailings is 1:4-12 based on the absolute dry tailings, the residual magnetic induction intensity of the magnetic powder particles is 0.15-2.5 mM, and the mass of the magnetic volcanic ash cementing material accounts for 5-10% of the total amount of the magnetic volcanic ash cementing material; The gel breaker comprises a high-valence metal cation inorganic flocculant; the ultrafine particle catcher comprises polyacrylamide.
  2. 2. The steel slag sand fine tailings composite filling mortar of claim 1, wherein the magnetic powder particles adopt magnetized steel slag micro powder or magnetic concentrate powder or a combination thereof, and the specific surface area is 300m 2 /kg≤S≤700m 2 /kg.
  3. 3. The steel slag sand fine tailings composite filling mortar according to claim 1, wherein the pozzolan component adopts natural pozzolan or artificial pozzolan, wherein the artificial pozzolan is at least one of water quenched blast furnace slag powder, fly ash and slag powder, and the specific surface area is more than or equal to 400m 2 /kg; The exciting agent comprises an alkaline exciting agent and a sulfate exciting agent, wherein the mass of the alkaline exciting agent and the mass of the sulfate exciting agent respectively account for 5-25% and 10-25% of the total amount of the magnetic pozzolanic cementing material.
  4. 4. The steel slag sand fine tailings composite filling mortar according to claim 1, wherein the fine tailings are full tailings or overflow graded tailings obtained by grinding pyrite or magnetite and magnetic separation beneficiation, the tailings concentration of the fine tailings slurry is more than or equal to 45%, and the slump is more than or equal to 180cm; The steel slag sand adopts hot closed slag, roller air-cooled slag or hot splashing slag generated in converter steelmaking, and takes absolute dry tailings in fine tailings as references, wherein the mass ratio of the steel slag sand to the absolute dry tailings is 1:3-12.
  5. 5. The steel slag sand fine tailings composite filling mortar of any one of claims 1 to 4, wherein the ultrafine particle capturing agent is any one of anionic polyacrylamide, cationic polyacrylamide and nonionic polyacrylamide, and the mass ratio of the ultrafine particle capturing agent to the absolute dry tailings is 1:10000-1000000; the gel breaker adopts polymeric ferric chloride or polymeric aluminum chloride or a compound of any mass ratio of the polymeric ferric chloride or the polymeric aluminum chloride and the absolute dry tailings, and the mass ratio of the polymeric ferric chloride or the polymeric aluminum chloride to the absolute dry tailings is 1:500-3000.
  6. 6. The steel slag sand fine tailings composite filling mortar according to claim 5, wherein the steel slag sand fine tailings composite filling mortar sample is maintained under the conditions of 20 ℃ and relative humidity of 90%, wherein the 3-day unconfined compressive strength is not less than 1MPa, the 7-day unconfined compressive strength is not less than 1.8MPa, and the 28-day unconfined compressive strength is not less than 3MPa; After the steel slag sand fine tailings composite filling mortar sample is placed in 10atm water vapor for curing for 3 days, the unconfined compressive strength is more than or equal to 3.5MPa.
  7. 7. A method for preparing the steel slag sand fine tailings composite filling mortar according to any one of claims 1 to 6, which is characterized by comprising the steps of mixing raw materials of the steel slag sand fine tailings composite filling mortar and uniformly stirring to obtain a steel slag sand fine tailings composite filling mortar sample.
  8. 8. The preparation method of the steel slag sand fine tailings composite filling mortar is characterized by further comprising the step of placing the mixed steel slag sand fine tailings composite filling mortar sample in an external magnetic field for magnetization treatment, wherein the intensity of the external magnetic field is not less than 0.1T, and the magnetization time is 0.5-5 seconds.
  9. 9. A method for using the steel slag sand fine tailings composite filling mortar as set forth in any one of claims 1 to 6, wherein the prepared steel slag sand fine tailings composite filling mortar is filled into an underground space to be backfilled.
  10. 10. The use method of the steel slag sand fine tailings composite filling mortar according to claim 9 is characterized by further comprising the step of applying an external magnetic field to the filling mortar in the process of filling the prepared steel slag sand fine tailings composite filling mortar into an underground space to be backfilled, wherein the intensity of the external magnetic field is not less than 0.1T, and the magnetization time is 0.5-5 seconds.

Description

Composite filling mortar of steel slag sand fine tailings and preparation and use methods thereof Technical Field The invention belongs to the technical field of tailing cemented filling materials, and particularly relates to steel slag sand fine tailings composite filling mortar and a preparation and use method thereof. Background There is an increasing demand for mineral resources by industrial society. The mining brings mineral resources, and simultaneously generates a large number of goafs and tailing reservoirs on the surface, thereby bringing great potential safety hazards to enterprises and society, namely goaf collapse and tailing reservoir collapse. Mine filling is an effective means for treating mining collapse, and students at home and abroad have conducted a great deal of research on the mine filling, so that a plurality of effective methods are provided. Filling mining and filling process technology are becoming more and more important and are continually improving. On one hand, the novel filling material which has wide sources, low cost and higher strength of the filling body is researched and developed through deeper understanding of the physical and mechanical properties of the filling material and the filling body, and on the other hand, the novel filling process and mode are researched through the discussion of the mechanical action mechanism of the filling body under the geological conditions of mining and combining with the mining operation requirements. The cemented filling is divided into graded filling and full-tailing filling, wherein the graded tailing sand filling process is characterized in that the tailing sand is subjected to graded desliming treatment, coarse-grain-diameter particles are taken as aggregates, and cement is taken as cementing materials, so that the filling tailing slurry enters a stope to be dehydrated rapidly, and the strength of a filling body can be obviously improved, and therefore, the graded tailing sand filling process is the most widely applied method in mine filling processes at home and abroad. The full tailing sand cemented filling is a filling mode of taking full-size-grade tailing sand without grading desliming as filling aggregate, uniformly mixing and stirring the full-size-grade tailing sand with cementing materials and water according to a certain proportion, and filling the full-size-grade tailing sand into a goaf under a well. As a novel and efficient filling mode, the full tailing sand cemented filling can maximally utilize tailing resources, and reduce pollution of tailings to the environment and resource waste. Although the cemented filling has the advantages of simple filling system process, low filling slurry concentration, convenient slurry preparation and transportation and the like, at least one of the following problems exists: 1) The tailing utilization rate is low, and fine-fraction tailings are difficult to treat. When coarse tailings are used as aggregate, the whole tailings are subjected to classification, fine fraction is removed, the particle size of the part of tailings is very small, the tailings are difficult to solidify, the solidification strength is low, and the dam is difficult to build, so that the treatment difficulty of the tailings is further increased, the construction cost of a tailings pond is increased, and the environmental pollution is aggravated; 2) For partial ores with complex occurrence conditions and lower grades, further fine grinding is needed to improve the recovery rate, so that the average grain diameter of ore bodies is smaller than 0.03mm, the size of-800 meshes is larger than 50%, the size of +200 meshes is smaller than 10% and the size of +400 meshes is smaller than 30%, the sedimentation speed of the superfine full tailings is low, the thickening is difficult, the permeability is poor, the dehydration is difficult, the pore pressure of the tailings is large, and the consolidation strength is low. 3) The filling cost is high. In the filling mining method, the filling cost is high, the filling cost is about 20% of the total mining cost, and the filling cost is even up to 40%, wherein the cementing material cost is about 75% of the total filling cost. The classified superfine tailings, the superfine full tailings and the tail mud are extremely fine in size, and become colloid, and then carry excessive micelle water, so that the problems of low cementing strength, difficulty in cementing and the like are caused, the use amount of cementing materials is increased, the filling cost is further increased, and the filling cost is high. The strength and cost of the cemented filling body are mainly determined by the properties of tailings, the concentration of filling slurry, the selection of cementing materials and other factors, and especially the granularity of tailings in the tailings slurry and the bulk density after filling, therefore, the intensive study of novel, low-cost, high-early-strength and hig