Feasible Study On Drawing Of Basalt In Changbai Area And Preparation Of Lightweight Ceramsite From Tailings

Continuous Basalt Fiber?CBF?is an inorganic non-metallic fiber which was produced by melting and drawing basalt.In addition to high mechanical properties,continuous basalt fiber also has much special properties,such as great insulation performance,excellent temperature and corrosion resistance,strong radiation resistance,microwave absorpting,wide temperature range and so on.The hygroscopeicity,alkali resistance and other aspects of CBF are also significantly better than glass fiber.The CBF is an eco-friendly material in 21 st century due to its large length-diameter ratio and difficult to be inhaled by the lungs.It is reported that the basalt reserves of Jilin Province is account for about 12% of China.The basalt in Changbai area of Jilin Province was characterized by rich in Fe O and Na₂O + K₂O,which can be classified into the coarse basalt.The CBF was prepared by compounding basalts which are from different Changbai areas,and lightweight ceramsite was prepared from basalt tailings,oil shale and other solid,this strategy could realize the comprehensive utilization on resources.The basalt was analyzed by XRF,and the suitable basalt was selected to drawing fibers according to the test results.The tested basalt to prepare CBF includes two calcined samples which were obtained by furnace cooling and quick-quenched followed by sintering at 1100¹450°C.Results of XRD and the polarizing analyze showed that only the quenching samples at 1450°C preserved for 9 h were suitable to drawing requirements.The diameter,linear density and the breaking force follows a decreasing trend with the increasing of the drawing velocity the CBF with a diameter of 11.5¹6.2 ?m obtained.When the drawing velocity was 7.2 m/s,the diameter of fiber was 12.6 ?m,the linear density was 3.54 Tex,and the breaking strength was 0.41 N/Tex.When the drawing velocity was 8 m/s,the diameter of fiber was 11.5 ?m and the linear density was 3.39 Tex,and the breaking strength was 0.40 N/Tex.The basalt tailing and the white mud as scaffolds for sintering ceramsites,the oil shale as foaming agent and the black cotton soil as fluxing materials was utilized to invent the ceramsite in the second part of this parper.A lightweight ceramsite that meet GB/T 17431-2010 was successfully prepared according to a certain ratio and sintering strategy.The sample was prepared with a mass ratio of basalt: white mud: black cotton soil: oil shale = 2:1:1:1,the sintering strategy is a staged sintering method,the sample is pre-sintered at 450°C for 15 min,then the sample was calcined at 1180°C for 20 min.The bulk density of the lightweight ceramsite was 662 kg/m³,the density grade was 700,the water absorption was 1.61%,the total porosity reaches 41.43%,and the cylindrical compressive strength was 4.21 MPa.The bloating mechanism,mineral transformation and micromorphology of ceramsite were investigated by X-Ray Powder Diffraction?XRD?,thermogravimetric?TG?,Electron probe X-ray microanalyzer?EMPA?and scanning electron microscopy?SEM?.The following two requirements are be satisfied to successfully make bloating ceramsites:?1?the raw pellets should generate vitrification when they are fired at a suited temperate,and the vitrification was viscose enough to trap the gas bubbles which were liberated by foaming agents;?2?the raw pellets must generate gaseous pores after the raw material was sintered to a viscous melt.This paper corrected the Riley diagram and the result would be a relatively reliable theoretical basis for the preparation of bloating ceramsite.To produce CBF with a diameter of 13 ?m the costs was evaluated to be approximately 9289 ?/t.The current market price is 16,000²3,000 ?/t for CBF.The cost of producing lightweight ceramsite is 340.45 ?/t,and the price of lightweight ceramsite is 400⁶00 ?/t.On condition that the lightweight ceramsite was used as ceramsite filter material,the price is as high as 2,000 ?/t.All these data indicate that the exploitation and utilization of basalt are of great significance to local economic development and environmental protection.