铁尾矿干压免烧砖的制备

以陕西某铁尾矿为主要原料，添加少量水泥及适量当地河砂，制备MU15级干压免烧砖，研究了铁尾矿与河砂的质量比、水泥用量、拌和用水量、成型压力以及化学外加剂对尾矿免烧砖抗压强度的影响。结果表明：在成型压力为15 MPa条件下，铁尾矿与河砂的质量比为1.25∶1.00，水泥在固体干料总量中占10%，拌和用水量为固体干料总量的8%，萘系高效减水剂掺量为水泥量的0.8%，葡萄糖酸钠缓凝剂掺量为水泥量的0.03%时，可制得28 d抗压强度达到16.4 MPa的铁尾矿免烧砖，其各项性能指标符合JC/T 422-2007《非烧结垃圾尾矿砖》标准的规定。

Preparation of Dry-Pressed Unfired Bricks Made of Iron Tailings

MU15 dry-pressed burning-free bricks were made with iron tailings from Shaanxi as the main raw material, and by addition of a small amount of cement and a proper amount of river sands.The effect of the mass ratio of iron tailings to river sand, cement amount, water addition for mixing, forming pressure and chemical additives on their compression strength was investigated.The results indicate that their 28 d compression strength can reach 16.4 MPa when they are made of iron tailings at such conditions: a forming pressure of 15 MPa, a mass ratio of iron tailings to river sand of 1.25∶1.00, a cement amount accounting for 10% of the total dry solids, a water addition for mixing amounting to 8% of the total dry solids, and a naphthalene-based super-plasticizer content and a sodium gluconate content of 0.8% and 0.03% of the cement dosage respectively.Their other performance indexes are in conformity with the requirements in JC/T 422-2007 standard “Unfired Bricks Made of Tailings”.