Study on Flotation Tailings of Kaolinite-type Pyrite when Used as Cement Admixture and Concrete Admixture

In Southwest China, the pyrite resources are very rich and the proven reserves of pyrite ranks first in the country. In the past 50 years of mining and processing, hundreds of millions of tons of tailings have been produced. However, the tailings have not been used effectively as yet, causing adverse effects to the local ecological environment. Therefore, according to the characteristics of the tailings, this article has studied on the pozzolanic activity of the tailings when used as cement admixture and the optimal amount of the tailings when used as concrete admixture. The results show that, being calcined on appropriate temperature and ground to certain fineness, the tailings will be provided with high pozzolanic activity. The activity index is up to 120%, so the tailings can be used as fine cement admixture and high-performance concrete admixture. The concrete will be provided with the highest compressive strength and still have good workability when the tailings replace cement for 20% by weight. The treatment method which gives a new approach for the efficient utilization of the tailings features simple production process, low energy consumption, no secondary pollution and high consumption of the tailings.