| Mineral resources are the foundation of national economic development and mining industries support the operation of national economy.However,a great quantity of solid wastes(for example: tailing sand)are produced when human beings obtain mineral resources,so these tailing sand must be disposed effectively.Presently,mining enterprises' disposing method is usually filling goaf with Graded-tailing-sand and cement,and Overflow-tailing-sand(ultra-fine)is stored up in the Tailing-sand-reservoir by transportation.On the one hand,the Tailing-sand-reservoir brings huge costs of infrastructure and operation,on the other hand,it brings great pollution to the surrounding environment and threatens the surrounding residents' lives and property.Therefore,in order to stop producing tailing-sand and eliminate Tailing-sand-reservoir,we must utilize all of full-size-tailing-sand.Presently,studies of utilizing all of full-size-tailing-sand are almost filling goaf with cement,but my study is utilizing all of full-size-tailing-sand to fill goaf with a new kind of cementing material.This kind of cementing material is from a project called Preparation and Application of New Filling Materials for High Efficiency Utilization of Solid Waste Resources.The formula range of this kind of cementing material is 45%~60% of slag powder,18%~26% of fluorgypsum,15% of P·O 42.5R cement,4%~6% of quicklime?2%~4% of sodium hydroxide?1%~2% of compound additive.The main contents and conclusions of my studies are:(1)Locally investigate and research,be familiar with filling technique and filling system,master the actual filling requirements and clarify the test objectives,collect material samples.(2)Three methods are used to analysis physicochemical properties of material samples.These methods include X-ray fluorescence(XRF),X-ray Diffraction(XRD)and Laser particle size analyzer.Definite key testing parameters of material samples,these parameters include chemical constituents and compositions and particle-sizedistribution and so on.The conclusion is that: full-size-tailing-sand of a lead-zinc mine in South China is fine tailing sand.(3)Design indoor proportioning testing scheme and conduct proportioning test.Three methods are used to analysis testing results.These methods include line chart,range analysis and variance analysis.The conclusions are these: 1)Filling capacities of this cementing material is better than cement when it is under the same conditions.These filling capacities include compressive strength of filling block and fluidity of filling slurry.2)For this cementing material,lime-sand-ratio have a bigger effect on compressive strength of filling block than mass-percentage-concentration,but it have a smaller effect on fluidity of filling slurry than mass-percentage-concentration.3)limesand-ratio and mass-percentage-concentration have a very significant effect on compressive strength of filling block and fluidity of filling slurry.(4)Design numerical simulation scheme for pipeline transportation and conduct numerical simulation.Two methods are used to analysis results of numerical simulation.These methods include comparative analysis and controlling variable.The conclusions are these: 1)slurry of this cementing material have a better capacities of pipeline transportation than cement when it is under the same conditions.2)Pipeline inner diameter has great influence on pipeline transportation of this cementing material's slurry.Therefore,much attentions should be paid to the selection of pipeline inner diameter when designing filling system.3)It can reduce pressure of drainage underground mine,reduce filling cost and increase utilization ratio of full-size-tailingsand when increasing mass-percentage-concentration.Therefore,it should increase mass-percentage-concentration of slurry as much as possible under the condition of feasible filling. |
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