Formation of traditional vanadium extraction process

Formed stone coal vanadium traditional process

In 1958, Hunan Province metallurgical exploration companies find the newly opened vanadium ore. The Hunan Metallurgical Research Institute immediately carried out an optional test for the enrichment of vanadium in stone coal , and the conclusion was “not optional”. Since then, the Institute has carried out experimental research on the extraction of vanadium directly from vanadium-bearing coal. From 1961 to 1964, it has completed a small test and a processing capacity of 13,357 tons [dry mining industrial rotary kiln semi-industrial production test. V2O>5590 kg (according to 100%)], the content of V2O5 is 73%-83%, and the total recovery of vanadium is 44%. Due to the complexity of the process equipment, high technical requirements, large power consumption, gas or heavy oil is also required as fuel, and the investment in construction is large and the construction period is long. Therefore, the domestic vanadium smelters built with this technology have been delayed in production [4 ~ 5]. In the early 1970s, the Central South Institute of Mining and Metallurgy (now Central South University) was the mainstay. The experimental research work on extracting V2O5 from Anhua Yanzhu Stone Coal was completed with the relevant units. Laboratory tests, semi-industrial tests and industrial tests were completed. The experimental Anhua manufacturer pioneered the flat kiln for the self-heating sodium roasting of stone coal on the basis of the vertical kiln, and it is still used in various vanadium plants [6-8]. In 975, the Zijiang Chemical Plant in Anhua County built a small-scale soil test production line, which was renamed as Anhua County Vanadium Plant, and was the first professional vanadium production plant in Hunan. According to the arrangement of the Science and Technology Commission of Hunan Province, in March 1976, Hunan Metallurgical Research Institute and Houyang Xinkai Commune cooperated to conduct experimental research on the extraction of vanadium from stone coal and establish production. After the experimental study from March to June 1976, the technology of roasting vanadium in stone coal without coal, leaching without alkali, and vanadium is not concentrated [9]. The roasting equipment was selected from the flat kiln of the Anhua Vanadium Plant and improved. A chimney system with a flue gas distribution plate and a smoking system were added, which significantly improved the working conditions and improved the conversion rate of vanadium. Later, the crude vanadium (red vanadium) refining process was experimentally studied. By 1979, the traditional process of stone coal with salt, sodium oxide, roasting, water immersion, hydrolysis, coarse vanadium, crude vanadium refining, and refined vanadium had been formed. The traditional process of extracting vanadium from stone coal has the advantages of uncomplicated investment equipment, low investment, fast speed and little technical difficulty, and is widely used. In the late 1970s, the number of vanadium extraction vanadium manufacturers using this process was up to 59 in Hunan Province, with a production capacity of nearly 10,000 t/a. Due to the change in vanadium prices, by the end of 1982, there were only four remaining in the province. The drawbacks of the traditional process are also obvious: long process flow, low metal recovery rate (<40%), high cost, roasting flue gas and heavy vanadium wastewater have serious environmental pollution [10]. In the past 20 years, in response to the shortcomings of the traditional process of extracting vanadium from stone coal, the scientific and technological personnel of Hunan universities and research institutes and the technicians of vanadium plants have carried out continuous technological innovations, which has raised the level of vanadium extraction from Hunan's stone coal to a new level.

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