4.9.2.1 Present State of Production

China began to produce potash at the end of the 1950s. Owing to the influences of such factors as resource conditions and technologies and techniques, the production has long been very low. In 1997 China's potash (KCl) production was 310,000 tons or 186,000 tons K2O equivalent, which was only 0.72% of the 25.7 million ton (K2O) world production in that year and 6.6% of the demands of China.

In recent years increasing attention has been paid to the use of potassium sulfate as fertilizers of economic crops and orchards with increasing demands for tobacco, fruits, vegetables and other chlorofuge crops. Before 1992, only the Wenzhou General Chemical Plant produced a small amount of potassium sulfate, and afterward some potassium sulfate plants were constructed in many areas. According to the statistics, up to the end of 1997, China had more than potassium sulfate production enterprises with a total production capacity up to 636,000 tons (Table 4.9.1). But owing to small scale and poor economic returns, their production was suspended intermittently. For the new plants whose pilot plant testing has been completed in the past two years, their operations are not ideal owing to such problems as insufficient experience, imperfect technology and incomplete equipment, though part of them have been up to the requirements of the reasonable economic scale. In 1996 their production was only 100,000 tons, in 1997 the production was 220,000 tons and in 1998 the production was 280,000 tons. With continued perfection of the technology and extension of part of the enterprises, however, it may be estimated that China's production of potassium sulfate can meet the domestic demands in the near furture.

Table 4.9.1 Major potassium sulfate production enterprises of China (up to 1997)

4.9.2.2 Distribution of Production

Potash production enterprises in China are mostly integrated minerals and fertilizers complexes. They are distributed very unevenly, mainly in Qinghai Province and less commonly in Yunnan and Sichuan.

The Qinghai Potash Fertilizer Plant is China's largest potash fertilizer production base. From 1958 when the plant began to produce potash fertilizer (KCl) with carnallite as raw material till the end of 1990, China had formed a production capacity of 270,000 t/a (KCl), or a K2O equivalent of 158,900 t/a. The production capacity of the plant in the second phase of construction is designed to reach 800,000 t/a (KCl). In May 1996 the Chinese government approved the feasibility study report, in which the cooling crystallization technique of Israel is to be used in joint works. In November 1998 the Chinese and Israeli parties signed a joint investment contract and an agreement of technical license and the Chinese government issued the certificate of approval of works. It is estimated that the proposed works will be completed and put into operation at the beginning of the 21st century.

The Mengyejing solid potash mine at Jiangcheng, Yunnan, is another large producer of potash in China. A pilot workshop which can produce 1,000 tons of KCl per year was completed at the beginning of the 1970's and later it was extended and was able to produce 10,000 t/a. In 1985 it was suspended because it was inundated by flood. Now its production is relatively small. The major KCl production enterprises of China are given in Table 4.9.2.

Table 4.9.2 Major KCI production plants in China