USE OF BORIC ACID AS A BINDER FOR BRIQUETTING SOME BORON MINE WASTES AND THEIR CALCINED PRODUCTS

摘要

In this study, boric acid as a binder for briquetting some boron mine wastes, such as colemanite and ulexite fines and calcined products, which do not meet the market specifications with respect to particle size, were investigated. Effects of water and binder contents, applied pressure, and curing and drying conditions on the briquette quality were evaluated in terms of mechanical strength, water-proofing characteristics and wearing resistance. The best briquettes were obtained at 62.4 MPa pressure (cured at ambient temperature for 24 h and dried at 105℃ for 2 h). Only binder free briquettes of uncalcined ulexite gave satisfactory result. The briquette strength increased with an increase in the percentage of binder. The optimum binder content was found to be 5 % by weight for uncalcined ulexite and colemanite as well as calcined colemanite, but 10 % by weight for calcined ulexite. The water-proof briquettes of ulexite and calcined products of ulexite and colemanite fines could be produced. According to wearing resistance, ulexite and colemanite fines as well as calcined product of colemanite showed resistance to abrasion action during transportation and loading.