Method for lixiviating molybdenum from roasted molybdenite

Abstract

The invention discloses a method for lixiviating molybdenum from roasted molybdenite. The method comprises the following steps of: 1, uniformly mixing the roasted molybdenite, ammonium carbonate and deionized water at a certain mass ratio, and then stirring for 40-70 minutes under the condition that the temperature is 70-90 DEG C to obtain a turbid liquid; 2, filtering to obtain a filter cake and filter liquor; 3, washing the filter cake by adopting ammonia water, then uniformly mixing the washed ammonia water with the filter liquor to obtain a mixed liquor; 4, regulating the pH value of the mixed liquor to 8.0-8.5, uniformly stirring, then carrying out sedimentation treatment, and taking a supernatant to obtain molybdenum lixivium. The process disclosed by the invention is simple, easy to operate, high in repeatability and suitable for large-scale industrial production, adopts the ammonium carbonate as a lixiviant, and can be used for greatly reducing the sludging ratio and the molybdenum content of dregs by regulating and optimizing the lixiviating process, and achieving the molybdenum lixiviating rate as high as more than 98%.

Description

technical field [0001] The invention belongs to the technical field of hydrometallurgy, in particular to a method for leaching molybdenum from molybdenum calcined sand. Background technique [0002] Molybdenum calcined sand, also known as industrial molybdenum oxide, is an important chemical raw material, which is roasted and smelted from molybdenum concentrate. Molybdenum calcined sand is used to prepare ammonium molybdate. Ammonium molybdate is an important chemical product, mainly used in powder metallurgy and electronics industry, and is the basic raw material for making molybdenum powder. In addition, molybdenum calcine can also be used as a catalyst, smoke suppression and flame retardant, pigment, etc. in the petroleum industry. [0003] In the process of using molybdenum calcine to prepare ammonium molybdate, ammonia leaching process is generally used to leach molybdenum from molybdenum calcine, so that molybdenum trioxide, the main component of molybdenum calcine, i...

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Problems solved by technology

[0004] However, this traditional ammonia leaching method has the following problems: 1. Molybdenum calcine not only contains molybdenum trioxide, but also a small amount of gangue minerals such as calcium molybdate, magnesium molybdate, iron molybdate, etc., wherein calcium molybdate and molybdate Magnesium is insoluble or hardly soluble in ammonia water, and after ammonia leaching, it enters the ammonia leaching residue, causing a large loss of molybdenum and affecting the leaching rate of molybdenum; 2. Ferric molybdate in molybdenum calcine meets alkali in the ammonia leaching process to form hydrogen oxidation Iron colloid, which wraps on the surface of molybdenum calcine particles in the form of a film, hinders the dissolution of molybdenum trioxide in molybdenum calcine and forms molybdenum trioxide aggregates

Calculated according to the existing water washing-ammonia leaching process, for every 100 tons of ammonium molybdate produced, 2.2 to 3.3 tons of molybdenum metal will be lost due to non-leaching, and the lost molybdenum exists in the ammonia leaching residue, while the ammonia leaching residue The treatment is cumbersome, and the process of recovering molybdenum is cumbersome, so it is necessary to increase the leaching rate of molybdenum calcined sand and reduce the loss of molybdenum in the slag

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