Study on the production of artificial sand from non-hazardous dredged sludge in Hanoi cityprinciple and factor affecting the ability to granulate

Abstract

Recycling dredged sludge from lakes, rivers, and estuaries into granular fill material as a substitute for natural sand has been studied by several countries around the world and gradually improved. However, this is still a new issue and has not been applied in Vietnam. This paper presents the manufacturing process diagram for converting sludge into R-GFM. In addition, the authors investigated the effects of moisture content, curing and remixing time, and the content of cement and polymer additives on grain formation. In the experiments, non-toxic West Lake sludge (B) was used with moisture content controlled within the range of [WP; WL]. The sludge was then mixed with cement (X) and polymer (P) additives. The product after mixing had
a granular shape, but the particles were still plastic because of the high moisture content of the sludge. The research results showed that the moisture content at mixing has a significant effect  on the grain formation of RGFM. R-GFM samples could not form grains in the first mixing when using sludge with high initial moisture content or sludge at the flow limit moisture content. However, the grain formation ability was.

Keywords: Artificial sand; recycled granular fill material (RGFM); manufacturing principle