Study Of Foam Concrete Using Phosphate Tailings

Phosphate rock is a kind of important chemical mineral raw material, which can be used to produce phosphate fertilizer, yellow phosphorus, phosphoric acid, phosphate and other phosphates. It can be divided into phosphorus concentration and phosphorus tailings by grade. phosphorus concentration is a higher grade, which can be used to produce products such as phosphoric acid ammonium phosphate, but phosphorus tailings is industrial wastes owing to its low grade. A series of problems such as occupying a lot of land, posing safety hazard, raising maintenance costs had been brought by phosphorus tailings. This topic that foam concrete preparation in use of phosphate tailings achieves the purpose of recycling, greatly reducing environmental pressure and economic costs.Foamed concrete is a kind of new lightweight thermal insulation material which contains a lot of closed porosity in structure. Foamed concrete is famous for it's advantage such as lightweight, heat preservation and heat insulation, sound insulation, impact resistant, fire prevention, etc. As a kind of energy-saving building materials, a bubble of concrete obtain widespread application. this paper aims to add phosphorus tailings as more as possible in the condition that compressive strength of foamed concrete preparation can achieve A3.5 B05 level standard, this research findings not only meet the requirements for use but also make use of waste.In this study density, compressive strength, frost resistance and dry shrinkage rate of foam concrete influenced by cement, silica fume, high efficiency water reducing agent, sodium silicate, hydrogen peroxide, calcium stearate, curing system, mold temperature and water cement ratio had been systematically researched. The best formula has been determined. By the way, another phenomenon has been discovered. has no activity, it can be only used as an inert filler. But after high temperature calcination, CaO and MgO that providing a certain activity will be genarated by dolomite, and then Phosphorus tailings can be used as active filler. It is proved by experiments that more than 8.6wt% Phosphorus tailings can be add when used as active filler in the condition that Compressive strength of foam concrete can meet A3.5 B05 level standard.In this paper, we using MicroCapture to take photographes for the foma concrete.Then, we using IPP(Image Pro Plus) to compare the different ways of treatment of the section processing to get the parameters of the pore structure. Finaly, we using the density and bulk density to calculae the porosity; using the IPP to count the average shape factor of the pictures of the cross-section of foam concreate which have been blacked; then fill the pores with calcium carbonate powder and using the IPP to count the average hole diameter by IPP. Then, studying the relationship between porosity, and average hole diameter; average shape factor and average hole diameter; the compressive strength and porosity or average shape factor and the realationship between the thermal conductivity and porosity. Then fitting the mathematical expressions.