硫酸亚铁作为降铬剂在水泥生产中的应用

Application of ferrous sulfate as a chromium-reducing agent in cement production

通过工厂试验验证了掺加FeSO_4·7H_2O可有效降低水泥中水溶性六价铬含量,随着时间推移,其还原性效果略有降低,工厂应用时应根据还原剂掺加方式、空白水泥中六价铬含量及储存周期通过试验论证最佳掺量。磨前及磨后掺加各有利弊,磨前掺加均匀性较好,但影响还原剂的还原效果;磨后掺加虽然能够降低还原剂被氧化现象,但是还原剂易结块,大颗粒还原剂与水泥不易混匀。掺加少量的FeSO_4·7H_2O验进一步论证。FeSO_4·7H_2O对于不同品种水泥、减水剂相容性的影响应通过试验具体论证。

The results of factory test showed that the water soluble hexavalent chromium content in cement could be reduced by adding FeSO4·7H2O.Its reducing effect is slightly reduced over time.Factory application should be based on the method of reducing agent admixture,blank cement hexavalent chromium content and storage cycle,through the experiment to prove the best dosages.There are advantages and disadvantages of mixing before and after grinding.The uniformity before grinding is good,but the reduction effect of reducing agent is affected.Although the addition after grinding can reduce the oxidation of the reducing agent,the reducing agent is easy to lump,and the large particle reducing agent and cement are not easy to mix.The addition of a small amount of FeSO4·7H2O has little effect on the performance indicators such as water demand,setting time,and strength of cement.The maximum allowable admixture should be further demonstrated by experiments.The effect of FeSO4·7H2O on the compatibility of cement and water-reducing agent should be demonstrated by experiments.