No Optimism for Boron Resources    
By Zheng Xuejia   

Boron resources are abundant around the world. The total reserves reportedly amount to 333.63 million tons (counting on boron trioxide). The proven boron ore reserves in China amount to 38.886 million tons, accounting for 11.6% of the world's total, mainly distributed in 10 provinces and autonomous regions such as Liaoning, Qinghai, Tibet, Hunan and Jilin. China has considerable boron ore reserves, but the quality of boron ores here is much lower than in other countries. The usable resources are therefore limited. Furthermore, great quantities of high-quality boron ores are located in Qinghai and Tibet where conditions for transportation and mining are poor. Therefore certain constraints limit the development of China's boron industry.
   Most boron ores in China are low grade. Boron ores with a boron trioxide content of no more than 12% account for 90.74% of the total reserves and rich ores with a boron trioxide content of no less than 20% account for only 8.54%. More than 95% of mineral raw materials used in the boron industry of China are boromagnesite ores, but boromagnesite ores account for only 6.64% of the total reserves in China. Paigeite ore reserves account for 58.54% of the total, but China has yet no well-developed paigeite ore processing technologies, and commercial utilization is still at the initial stage. Boron resources in salt lakes account for 33.13% of the total boron ore reserves in China, but they are mainly distributed on the Qinghai-Tibet Plateau and are difficult to develop and utilize due to difficult transportation and mining conditions. Other boron ores account for 1.69% of the total reserves and are commercially insignificant.
   China lacks boron resources. Its recoverable reserves of high-quality boromagnesite resources are already close to exhaustion. With the rapid development of China's national economy, the demand for boron resources is increasing steadily, sustaining a serious supply shortage. The annual output of borax has been around 300 000 tons in China in recent years and the annual output of boric acid is between 80 000 tons and 100 000 tons with no great fluctuations. The amount of boric acid and borax imported, combined, is usually 600 000-800 000 tons a year, mainly from Turkey, Russia and Chile. The amount was the highest in 2008 and dropped by around 14% in 2009.
   Boromagnesite ores in China have a relatively high grade, but the proven remaining reserves of boromagnesite ores amount to less than 3.0 million tons today, and due to technical problems only 50% of the reserves can be mined. With the depletion of the remaining reserves, the difficulty in mining is increasing. The reserves of paigeite ore in Liaoning province account for 58.0% of the total boron ore reserves in China and can be used for 50-100 years. Due to the complicated structure (the average boron trioxide content being 7.5% and the ferrous content being 30%), however, utilization has not been adequate in the past. Through many years?efforts, breakthroughs have finally been made in process technologies for dressing and separation. Separation technology using both magnetism and gravity can sort boron concentrate with a boron trioxide content of more than 12% and boron-containing iron concentrate with a ferrous content of 53%-55% from paigeite ores. This method has laid a foundation for development of the remaining boron resources in China.
   In light of experiences in other countries, China can leave the processing of boron ore for which the current separation machinery is unsatisfactory, such as paigeite ores, till a later time when the technology makes further advances. But the country needs to strengthen its development and utilization of boron resources in brine.
   Rich boron resources lie in the western region of China. Due to long transport distance and poor mining conditions, however, great quantities of boromagnesite ores with a boron trioxide content of around 20% are discarded as lean ores. Resources are seriously wasted. China should therefore change the locally-used extensive mining method into semi-mechanical mining-dressing method so as to increase the grade of ore. In this way, the transportation cost can be reduced, the utilization rate of resources can be increased and a foundation can be laid for the development of the local boron industry and the development of backup resources.