An Acid Process to Concentrate Oxidized Tungsten-Molybdenum Ore

In recent years, the improvement of the metallurgy and the improvement of the concentration capacity of the oxidized tungsten-molybdenum ore have been greatly improved. For example, Gansu, Qinghai, Xinjiang, Inner Mongolia and other provinces now, has the ability to have a froth float on tungsten-molybdenum ore with a tungsten trioxide content of 3 to 8%, and a molybdenum content of 2.5 to 12.5%; The Guangdong and Guangxi regions have the ability to have a froth floatation on tungsten-molybdenum ore containing 20 to 45% of tungsten trioxide and 10 to 25% of molybdenum.

In the froth flotation process, how to carry out the wet metallurgy process for the concentration of tungsten-molybdenum ore, improve the grade of tungsten and molybdenum in their respective mines, promote the separation of tungsten and molybdenum, and complete the new process of tungsten-molybdenum metallurgy to obtain WO3 and MoO3 products are the main difficulty of the process. Some scholars have achieved this goal using the acid process. The process adopted by the method includes: concentrated acid pretreatment, leaching, precipitation, MoO3 calcination, ammonia leaching, concentration, cooling crystallization, and WO3 calcination. The contents are as follows:

A. Concentrated acid pretreatment: In the acid-resistant enamel kettle, 100 kg of tungsten-molybdenum ore powder containing 3.5% of molybdenum and 3.5% of tungsten trioxide is added, and the theoretical amount of acid and the calcium molybdate contained is 1.5-3.5 times. Concentrated acid (HCl or HNO3) or mixed acid, stir well, pre-treatment at room temperature for 0.5 ~ 2.5h.

B. Leaching: After pretreatment of concentrated powder of mineral powder, the solid-liquid ratio is controlled to 1:2, the pH value of the solution is 0.1-0.5, the reaction temperature is 15 °C-95 °C, and the reaction time is 0.5-5.5 h. After the completion of the reaction, the solid-liquid separation was carried out to obtain a solid concentrate of 36 kg of tungsten concentrate, a liquid containing molybdenum of 17.4 g/L, and a molybdenum leaching rate of 99.3%.

C. Precipitation: Keep the liquid temperature 30 ~ 80 ° C, pH value 1.5 ~ 2.8, time 0.5 ~ 1.5h, add 10kg of ammonium chloride to help sink, get H2MoO4 precipitation under stirring, solid-liquid separation, filter cake for molybdenum product.

D. MoO3 calcination: The filter cake is dried at 100 ° C, and calcined at 300 ° C to 550 ° C to obtain 5.10 kg of molybdenum trioxide containing 67% molybdenum, and the total recovery of molybdenum is 98.5%.

In the acid process, the presence of molybdenum in the tungsten-molybdenum oxide ore is molybdenum or calcium molybdate, the molybdenum content is 3.5%, and the ore particle size is -150 mesh 80%. The acid used is a mixed acid of one or more of hydrochloric acid, sulfuric acid, and nitric acid. The method has the advantages of less loss of tungsten and molybdenum, high recovery rate, low cost and simple process, and is an effective means for enriching tungsten-molybdenum ore.

• < Prev
• Next >