Yunnan Bureau of Geology and Mineral Resources began to pay attention to the potash mines in Laos at the end of the 20th century. In July, 20001year, China signed an agreement with the Lao government to explore and develop potassium salt in Vientiane basin, starting with exploration. The mining area is 78 square kilometers. After two years and eight months of exploration, 53 boreholes were drilled and 38 of them were found. There are many different data about controlled resources/reserves. In June, 2004, Yunnan Zhongliao Mining Development and Investment Co., Ltd. and the Lao government signed the Agreement on Potash Mining and Production in Vientiane Basin, Laos. At that time, the project was valued by the party and state leaders, and government departments at all levels also gave strong support.
Because the potassium salt in Vientiane Basin is mainly carnallite with low grade, the production process of extracting potassium salt is complicated. Using selective leaching technology, the production cost of potassium chloride per ton reaches 5000 yuan, which is not competitive in the market. The Lao government has a strong sense of environmental protection, and the task of eliminating magnesium chloride pollution from tailings is arduous. Time has passed 10 years, and the original planned annual output 10 million tons seems to be far away. At present, an industrial test with an annual output of 50,000 tons of potassium chloride has been drawn up, and this plan has not yet been completed. At present, the cooling crystallization process of vaporization separation is adopted in Zhongliao mining industry, and the cooling crystallization temperature is controlled at 10 ~ 30℃, and then solid-liquid separation is carried out by centrifugal separation to obtain solid potassium chloride. The mining area is located near the capital and near the Lancang River, and the investment in environmental protection accounts for a high proportion of the cost. The production cost of potassium salt has yet to be tested.
As a pioneer of overseas potash exploration and development, why did it fall into the current predicament? This is because only the urgent demand for potassium salt resources in China was considered when the project was established. The Vientiane Basin in Laos has great potential for potash resources, and Laos is a friendly neighbor of China. Especially according to the traditional concept of geological exploration, as long as the ore quantity can be detected, if there is a prospect of large and extra-large deposits, it is easy to establish a project. However, the problems of cost estimation, ore washability and environmental protection in general economic evaluation are ignored. Overseas exploration and options of China potash have reached Canada, Brazil, Thailand, Congo (Brazzaville), Ethiopia and other countries. The potash project in Laos is no longer the focus of people's attention, but the experience and lessons left by overseas potash exploration and development are also the wealth for us to "go global".