A kind of phosphogypsum cement retarder and preparation method thereof

Abstract

The invention relates to a phosphogypsum cement retarder. The cement retarder is composed of the following raw materials in weight percentage: 30%-65% of phosphogypsum, 3%-15% of lime, 5%-35% of alunite powder or 7%-40% of alunite, 8%-40% of slag . Compared with the prior art, the present invention has the beneficial effects that: the process of calcination into balls is omitted, and the processing of phosphogypsum is facilitated; the 28-day compressive strength value of cement is significantly improved, so that the same cement strength value is to be maintained. It can increase the amount of admixture in cement and bring economic benefits to cement enterprises.

Description

technical field [0001] The invention belongs to the technical field of preparation of cement retarders, in particular to a cement retarder and a preparation method. Background technique [0002] Phosphogypsum is a solid waste of the phosphate fertilizer industry. With the rapid development of high-concentration compound fertilizer industry in recent years, the phosphogypsum discharged by phosphate fertilizer chemical enterprises exceeds tens of millions of tons every year. As one of the main raw materials for engineering and construction, cement is widely used. In addition to cement clinker, slag, fly ash and other materials obtained by calcination, in order to make the cement set properly, a small amount of Retardant, natural gypsum is a commonly used one, generally added in an amount of 3% --- 5%. Most of the natural gypsum in our country is used as a cement retarder. Cement is a hydraulic gelling material that hardens after hydration. During its hydration process, the m...

AI Technical Summary

Problems solved by technology

At present, some cement retarders produced with phosphogypsum as the main raw material have the following problems: one is that the proportion of the added auxiliary materials is unreasonable, it is difficult to mix evenly in actual operation, and the quality characteristics cannot be guaranteed, so the uniformity and stability of the cement setting time cannot be ensured. ; The second is that the treatment requires calcination and ball formation, and the process is cumbersome, so it is difficult to popularize and apply