铜尾矿免烧墙体材料的研制

Development of non-burning wall material of copper tailings

通过正交试验优化固化剂配比,并通过单因素试验探究固化剂掺量对铜尾矿免烧墙体材料抗压强度、软化系数和导热系数的影响。采用XRD、SEM分析材料的固化机理。结果表明,固化剂的最优配比为:钒铁渣、矿渣粉、熟石灰、脱硫石膏和石灰石粉用量分别为30%、40%、20%、4%和6%;最佳固化剂掺量为20%,材料7、28 d抗压强度分别大于17、22 MPa,软化系数分别为0.65和0.77,导热系数为0.8683 W/(m·K)。免烧材料的固化机理是:固化剂与铜尾矿反应生成Ca_(6)Al_(2)(SO_(4))_(3)(OH)12·26H2O(钙矾石)及Ca_(4)Al_(2)O_(7)·13H2O(水化铝酸钙);固化剂中C2S的水化反应增加了材料内部结合力和密实度,从而使材料具有较高的强度和耐水性。

Orthogonal experimental was used to optimize the proportioning of curing agent.The influence of different content of curing agent on the compressive strength,softening coefficient and thermal conductivity of the material was studied by single factor experimental.The curing mechanism of the material was studied by XRD and SEM.The results show that the optimal proportion of curing agent is as follows:the content of vanadium iron slag,slag powder,calcium hydroxide,desulfurization gypsum and limestone powder is 30%,40%,20%,4%and 6%respectively.The optimal content of curing agent in material is 20%,in which the compressive strength of materials at 7 d and 28 d is greater than 17 MPa and 22 MPa respectively,and the softening coefficient is 0.65 and 0.77 respectively,the thermal conductivity of the material is 0.8683 W/(m·K).The curing mechanism of the material is that the curing agent reacts with copper tailings to form Ca_(6)Al_(2)(SO_(4))_(3)(OH)12·26H2O(ettringite)and Ca_(4)Al_(2)O_(7)·13H2O(hydrated calcium aluminate),the hydration reaction of C2S in the curing agent increases the internal adhesion and compactness of the material,thus making the material has higher strength and water resistance.