Feasibility Study Of Antimony Tailings Waste Rock Used As Concrete Coarse Aggregate

At present,China’s civil engineering construction volume and concrete consumption rank first in the world.As an important part of concrete,natural sand and stone face the crisis of resource exhaustion day by day.Mechanized sand and stone have been widely used in concrete,but the mining of natural stone will inevitably destroy the ecology,and bring noise,dust and other environmental pollution.Using tailings as aggregate in concrete,as a substitute for natural sand,can realize the transformation of waste into treasure and greatly reduce the production cost.Combined with the present situation of large amount of antimony tailings discharge and accumulation in tin mine of hunan province,the waste antimony tailings is firstly proposed to be used as coarse aggregate of high strength concrete.It is found that antimony tailings waste rock has the feasibility to be used as high strength concrete coarse aggregate through the systematic study of rock mechanical properties,chemical composition and aggregate characteristics of antimony tailings waste rock.The main research results of this paper include:（1）The research status of iron tailings and copper tailings used in concrete,including chemical composition,substitution of coarse aggregate,fine aggregate and cement for ordinary concrete,as well as the application of other building materials such as ultra-high performance concrete（UHPC）,self-compacting concrete（SCC）,asphalt concrete and so on,are reviewed.（2）The pollution status of antimony tailings waste rock was investigated.The antimony tailings waste rock was obtained by using five-point sampling method in Xishan Mine and processed into rock samples.The mechanical properties of the waste rock were tested and compared with the rock samples from the coarse aggregate field in the nearby quarry.The results show that the cubic compressive strength,cylinder splitting strength and cylinder elastic modulus of antimony tailings waste rock samples are 1.31,2.22 and 1.40 times that of ordinary rock samples,respectively.Therefore,antimony tailings waste rock has good rock mechanical properties and has the possibility of being used as concrete coarse aggregate.（3）In order to further determine the composition of antimony tailings waste rock,samples were prepared into antimony tailings waste rock with a particle size of 5～20mm for X-ray diffraction（XRD）analysis and chemical composition analysis.The results show that the chemical composition of antimony tailings waste is mainly Si O2,with the content of88.78%.The average contents of five kinds of heavy metals in antimony ore waste rock in descending order are Sb（0.967%）>As(98.435×10^-6)>Pb(11.400×10^-6)>Hg(5.349×10^-6)>Cd(0.124×10^-6).（4）Referring to the standard method,the indexes of antimony tailings coarse aggregate and quarry aggregate were tested simultaneously,and it was found that the indexes of some antimony tailings coarse aggregate were better than those of quarry coarse aggregate.The results showed that antimony tailings coarse aggregate met the technical requirements of high strength concrete coarse aggregate.