Factors Affecting the Dissolution of Gypsum-Bonded Roof Bolts

摘要

In support of its objective to improve mine safety, the Bureau of Mines has searched for better materials and systems to anchor roof bolts. This report describes a study on the effects of mine waters upon accelerated gypsum, one of the materials under consideration. The accelerated gypsum dissolved at an appreciable rate relative to an assumed 10-yr life span of a roof bolt. Surface orientation, initial ion concentration of a dissolving solution, and flow rate of the solution had substantial effects on the dissolution rate. Factors such as water-cement ratio, accelerator content, wax capsule additions to the gypsum in cartridge-installed bolts, surface area, temperature, and curing duration had little effect.