CN103265080A - Method for producing high-purity ammonium paratungstate from tungsten waste - Google Patents

Abstract

The invention discloses a method for producing high-purity ammonium paratungstate from tungsten waste, which comprises the following steps of: firing waste into waste tungsten oxide; adding an ammonia aqueous solution into a thermal reaction kettle, adding the waste tungsten oxide, and heating for reaction; after the solution is clear, filtering and reserving the filtrate; after the filtrate is cooled, pre-adjusting the ammonia concentration to 50-65g/L, and injecting into the thermal reaction kettle; introducing steam for heating; when the ammonia volatilizes until the pH value of the filtrate is reduced to 7.5 and the Baume degree Be is 1-2, stopping heating, and cooling to 50 DEG C; performing solid-liquid separation on the cooled filtrate to obtain an ammonium paratungstate crystal, swabbing off, and washing and soaking with an ammonium nitrate solution; swabbing off again for drying; and drying the ammonium paratungstate crystal to obtain high-purity ammonium paratungstate. The high-purity ammonium paratungstate prepared by the method disclosed by the invention has the advantages of high purity, good uniformity, normal distribution, complete development of crystal form, good component uniformity of chemical main content and excellent usability.

Description

A kind of tungsten waste material is produced the method for high-purity ammonium paratungstate

Technical field

The present invention relates to the decomposition technique of Tungsten oxide 99.999, the separation of foreign elements technology specifically is to adopt ammoniacal liquor decomposing oxidation tungsten, controls the method that solution ammonia concentration makes impurity purify away with oxyhydroxide or other forms simultaneously.

Background technology

China's tungsten ore reserves account for the over half of world's content, and along with the opening of world market, tungsten production development in recent years is swift and violent, brings several realistic problems: one, the tungsten product cost of material is constantly soaring, and cost increases, and enterprise's pressure is big.Type of production enterprises such as domestic tungsten enterprise ammonium paratungstate, Tungsten oxide 99.999, tungsten powder, tungsten carbide powder are in the majority, in pulverizing process, can produce the tungsten waste material unavoidably, as ground be scattered material, the heals that sieves, dust collecting system material, exhaust system material etc., the processing of these waste materials is directly connected to casting yield and the production cost of tungsten smelting enterprise, and how these being turned waste into wealth always is the difficult problem of tungsten smelting enterprise; Two, tungsten belongs to important national strategy resource, also be Nonrenewable resources, also national this several year vigorously advocate and support for resource-conserving, environmentally friendly Development patterns transition, and department drops into a large amount of human and material resources still, financial resources are devoted to development research tungsten waste material and are produced high-purity ammonium paratungstate.

The present waste disposal mode of a lot of domestic tungsten manufacturing and processing enterprise: ammonium paratungstate, Tungsten oxide 99.999 waste material directly drop into ball milling (when ore with), finish an ammonium paratungstate again and make operation, ammonium paratungstate is produced in regeneration, Production Flow Chart is roughly: ball mill crushing (6h) adds chemical reagent, high-temperature high-voltage reaction (8h) simultaneously, filters (3h), ion-exchange (24h), removes molybdenum (24h), condensing crystal (20h), this method treatment time is long, consume high, long flow path, the rate of recovery of tungsten is low.The casting yield of supposing above-mentioned per step process tungsten simultaneously is 99%, and casting yield only is 90% during to product, and this method tungstenic waste residue tungstenic amount height, is generally 4～8%, is difficult to be recycled.And tungsten powder, wolfram varbide waste material are sold downstream manufacturer production casting WC or low side Wimet mostly at a low price, and its added value of product is low, and its economic interests are impaired.

Summary of the invention

For effectively improving the casting yield of tungsten, reduce treatment scheme, reduce consuming, the invention provides the method that a kind of tungsten waste material is produced high-purity ammonium paratungstate.

Tungsten waste material of the present invention is produced the method for high-purity ammonium paratungstate, comprises following production stage:

(1) the tungsten waste material that will collect in advance is by rotary kiln blowing air calcining 0.5～1.5 hour under 750 ℃ of temperature, and it is standby that waste material is fired into useless Tungsten oxide 99.999;

(2) pre-configured ammonia soln, control ammonia concentration adds the ammonia soln that configures in the thermal response still between 70～100g/L, and is standby; Slowly add the above-mentioned useless Tungsten oxide 99.999 of having fired while stirring in the thermal response still, heating makes its reaction, the weight ratio of the useless Tungsten oxide 99.999 of ammonia soln and adding is 1:3～4, temperature control is per hour monitored ammonia concentration simultaneously at 60～90 ℃, guarantees that ammonia concentration is greater than 70g/L, if concentration does not reach specified requirement, should in time add strong aqua, treat to filter filtrate for later use when solution is clarified substantially;

(3) after above-mentioned filtrate is cooled to 50 ℃, preset ammonia concentration is squeezed into the thermal response still again between 50～65g/L, start to stir, lead to steam heating then, vapour pressure is 0.22～0.27MPa in the control reactor, and temperature is 80～100 ℃, makes ammonia volatilization to filtrate pH value drop to 7.5, degree Beaume Be=1～2 o'clock, stop heating, reach the requirement terminal point, be cooled to 50 ℃;

(4) above-mentioned cooled filtrate adopts vacuum filtration to carry out solid-liquid separation, make order of ammoniumparatungstate crystal, draining the back is 5% ammonium nitrate solution washing immersion with mass percent, drains again and waits to dry by the fire, order of ammoniumparatungstate crystal after the IR bake oven dry, is made high-purity ammonium paratungstate.

Described tungsten waste material is one or more in ammonium paratungstate, Tungsten oxide 99.999, tungsten powder, the wolfram varbide.

Compare with conventional waste disposal, entire treatment method of the present invention and technology thinking require all to have different, the high-purity ammonium paratungstate that makes, its purity height, good uniformity is normal distribution, crystal formation is grown complete, and the component uniformity of chemical main content is good, the use properties excellence; And the filter residue among the present invention can use purification repeatedly, and the practical efficiency of useless tungsten is near 98%.

Embodiment

(1) the tungsten waste material that will collect in advance (mixture of ammonium paratungstate, Tungsten oxide 99.999, tungsten powder and wolfram varbide) 700kg is by rotary kiln blowing air calcining 1 hour under 750 ℃ of temperature, and it is standby that waste material is fired into useless Tungsten oxide 99.999 815kg;

(2) the 90g/L ammonia soln with 3.0 cubic metres of preparations in advance adds in the thermal response still, the useless Tungsten oxide 99.999 815kg that slowly adds above-mentioned pre-burned while stirring, heating makes its reaction, temperature control is per hour monitored ammonia concentration simultaneously, when treating that ammonia concentration drops to 70g/L at 75 ℃, add the strong aqua 100L of 400g/L, continue concentration and evaporation, treat to filter filtrate for later use when solution is clarified substantially;

(3) after above-mentioned filtrate is cooled to 50 ℃, preset ammonia concentration is squeezed into the thermal response still again at 60g/L, starts to stir, lead to steam heating then, vapour pressure is 0.25MPa in the control reactor, and temperature is 90 ℃, makes ammonia volatilization to filtrate pH value drop to 7.5, during degree Beaume Be=1, stop heating, reach the requirement terminal point, be cooled to 50 ℃;

(4) above-mentioned cooled filtrate adopts vacuum filtration to carry out solid-liquid separation, make order of ammoniumparatungstate crystal, draining the back is 5% ammonium nitrate solution washing immersion with mass percent, drain again and wait to dry by the fire, with order of ammoniumparatungstate crystal after IR bake oven dry, namely obtain high-purity ammonium paratungstate product 874.9kg, purity reaches 0 grade of GB, can be directly used in production and sales.

Claims (2)

1. the method that the tungsten waste material is produced high-purity ammonium paratungstate is characterized in that, comprises following production stage:

(1) the tungsten waste material that will collect in advance is by rotary kiln blowing air calcining 0.5～1.5 hour under 750 ℃ of temperature, and it is standby that waste material is fired into useless Tungsten oxide 99.999;

(2) pre-configured ammonia soln, control ammonia concentration adds the ammonia soln that configures in the thermal response still between 70～100g/L, and is standby; Slowly add the above-mentioned useless Tungsten oxide 99.999 of having fired while stirring in the thermal response still, heating makes its reaction, the weight ratio of the useless Tungsten oxide 99.999 of ammonia soln and adding is 1:3～4, temperature control is per hour monitored ammonia concentration simultaneously at 60～90 ℃, guarantees that ammonia concentration is greater than 70g/L, if concentration does not reach specified requirement, should in time add strong aqua, treat to filter filtrate for later use when solution is clarified substantially;

(3) after above-mentioned filtrate is cooled to 50 ℃, preset ammonia concentration is squeezed into the thermal response still again between 50～65g/L, start to stir, lead to steam heating then, vapour pressure is 0.22～0.27MPa in the control reactor, and temperature is 80～100 ℃, makes ammonia volatilization to filtrate pH value drop to 7.5, degree Beaume Be=1～2 o'clock, stop heating, reach the requirement terminal point, be cooled to 50 ℃;

(4) above-mentioned cooled filtrate adopts vacuum filtration to carry out solid-liquid separation, make order of ammoniumparatungstate crystal, draining the back is 5% ammonium nitrate solution washing immersion with mass percent, drains again and waits to dry by the fire, order of ammoniumparatungstate crystal after the IR bake oven dry, is made high-purity ammonium paratungstate.

2. according to the described method of claim 1, it is characterized in that described tungsten waste material is one or more in ammonium paratungstate, Tungsten oxide 99.999, tungsten powder, the wolfram varbide.