Clean metallurgical system for preparing ammonium molybdate from molybdenite concentrate

Abstract

The clean metallurgical system for preparing ammonium molybdate from a molybdenite concentrate comprises a raw material preparation device, a clinker generating device, a clinker pretreatment device, an ammonium salt leaching, purifying and separating device, an acid precipitation and separation device, an ammonium salt conversion and separation device and an absorption device, wherein the raw material preparation device is provided with a molybdenite inlet and a calcium carbonate inlet; the clinker generating device is provided with a roaster, an oxygen inlet, a carbon dioxide outlet and a clinker fine-grinder; the clinker pretreatment device is provided with a pretreatment solution outlet and a pretreatment slag outlet; the ammonium salt leaching, purifying and separating device is provided with a leaching agent inlet, a solution purifying and liquid-solid separating device, a coarse ammonium molybdate solution outlet and a leaching residue returning outlet; the acid precipitation and separation device is provided with a precipitator inlet, a solid-liquid separator, a multiple ammonium molybdate intermediate product outlet, an acid precipitation mother liquor outlet and a pretreatment solution inlet; the ammonium salt conversion and separation device is provided with a size solid-liquid separator, a calcium sulfate solid-phase outlet, and an NH3 and CO2 gas outlet; and the absorption device is provided with an NH3 and CO2 gas recovery inlet, a CO2 gas recovery inlet, an ammonia water supplementing inlet and a re-synthesized leaching agent outlet. The clean metallurgical system is low in production cost, high in production efficiency and free from pollution.

Description

technical field [0001] The invention relates to a clean metallurgical system for preparing ammonium molybdate from molybdenite concentrate, belonging to the technical field of molybdenum smelting. Background technique [0002] Molybdenite concentrate is the most important mineral raw material for the preparation of ammonium molybdate. The methods of processing molybdenite concentrate to prepare ammonium molybdate products in the prior art mainly include oxidation roasting-ammonia leaching and full wet oxidation. [0003] Oxidation roasting-ammonia leaching method has mature technology, small investment, and is easy to master. More than 90% of ammonium molybdate is produced by this method, but this method has the following main problems: [0004] 1) A large amount of low-concentration SO is produced during oxidation and roasting of molybdenum concentrate 2 There is currently no economical and efficient treatment method for flue gas, which leads to serious environmental poll...

AI Technical Summary

Problems solved by technology

[0004] 1) A large amount of low-concentration SO is produced during oxidation and roasting of molybdenum concentrate 2 There is currently no economical and efficient treatment method for flue gas, which leads to serious environmental pollution;

[0005] 2) The oxidation roasting temperature is high (about 600°C), which is easy to cause MoO in the calcined sand 3 The volatilization loss of the molybdenite concentrate with low melting point and more impurities is easy to agglomerate during the sintering process, which will eventually lead to a low recovery rate of Mo in the concentrate;

[0006] 3) The rare element rhenium contained in the molybdenite concentrate is difficult to recycle, and almost all of it is discharged with the flue gas;

[0007] 4) The quality requirements for molybdenum concentrate are relatively high, and it is not suitable for processing complex ore and low-grade ore

[0012] 1) Due to the large amount of lime added, CaSO is generated 4 The amount of slag is large and the amount of slag is large;

[0013] 2) The clinker is leached under acidic conditions, the equipment is corroded seriously, and the operating conditions are poor;

[0014] 3) The amount of sulfuric acid is large, the circulation is difficult, and a large amount of difficult-to-treat acid-containing wastewater is produced;

[0015] 4) The molybdic acid obtained after calcium molybdate leaching by sulfuric acid also needs to be converted into ammonium molybdate product through ion exchange or solvent extraction, and the process is more complicated and the cost is higher;

[0016] 5) The process of ion exchange and solvent extraction produces a large amount of wastewater containing ammonia nitrogen, which increases the cost of treatment

[0018] 1) The solution is difficult to fully circulate;

[0019] 2) The ammonium carbonate that is continuously added to the system is eventually transformed into a by-product of ammonium sulfate with low value, which will inevitably lead to high production costs

Images