Abstract:In order to improve the mining efficiency and output of a potash mine in Qinghai province， the mining scheme of through wells is put forward， after water injection from horizontal wells， brine is extracted from vertical wells， which greatly increases the production of potassium salts. The sticking accident occurred in the initial stage of construction， which was perfectly avoided by optimizing mud formula， reasonable selection of bit and design of anti-sticking drilling tool. After the completion of 40 horizontal and vertical wells， the annual output of potash in this area has increased by 35000 tons， which proves that the scheme of using horizontal directional drilling technology to improve the efficiency and output of potash mining is feasible！ The related research results can provide theoretical basis and practical guidance for the subsequent use of horizontal directional drilling technology for soluble mineral exploitation.

Abstract:In the mining system of potassium salt mine of Ganmeng Province in Laos, the ventilating shaft passes through carnallite and halilith, which are easily soluble in water. After the ventilating shaft excavating, cavern phenomenon, a serious threat to the normal function of the shaft, is found behind shaft wall. In order to ensure the safety of shaft construction and the normal production, curtain grouting is adopted to control the disease of ventilating shaft. The closed curtain grouting technology is adopted with the method of grouting from the top to bottom and with effect checking while grouting to finish the reinforcement and water plugging. The cementing materials used for carnallite and halite layer were tested in laboratory, a new type of grouting material, brine + magnesium oxide slurry was determined together with the scientific grouting mix ratio. By the summarization, the design and construction experiences are accumulated for waterproofing and water blocking in potash mine mining process.