CN106346021A

CN106346021A - Method for preparing cobalt powder through high-pressure hydrogen reduction

Info

Publication number: CN106346021A
Application number: CN201610854226.7A
Authority: CN
Inventors: 陈飞; 陈青林
Original assignee: NANJING HANRUI COBALT CO Ltd
Current assignee: NANJING HANRUI COBALT CO Ltd
Priority date: 2016-09-27
Filing date: 2016-09-27
Publication date: 2017-01-25
Anticipated expiration: 2036-09-27
Also published as: CN106346021B

Abstract

The invention relates to a method for preparing cobalt powder through high-pressure hydrogen reduction. A dispersant is added to a cobalt salt solution, the mixture is evenly mixed and then added to a reaction kettle, ammonia water is added to the reaction kettle, the temperature is increased after even mixing, then hydrogen is introduced for a hydrogenation reduction reaction, temperature decreasing and material discharging are performed after the reaction ends, an obtained product is filtered, washed, then subjected to vacuum drying and finally crushed and screened, and the cobalt powder is obtained. The method adopts the simple process, and the prepared cobalt powder is spherical, has the particle size up to 0.4-4.5 micrometers, has uniform particle size distribution, has larger loose specific weight and good mobility and has very wide application fields.

Description

A kind of method that cobalt powder is prepared in high pressure hydrogen reduction

Technical field

The present invention relates to a kind of method that cobalt powder is prepared in high pressure hydrogen reduction, belong to technical field of fine.

Background technology

The application of cobalt powder and its extensively, is mainly used in hard alloy, catalysis, electronic device, Special Tool, magnetic material The fields such as material, battery and hydrogen-occlussion alloy electrode.In hard alloy and diamond tool field, super-fine cobalt powder is used as binding agent.I The yield of state's hard alloy and diamond tool is huge, therefore will need substantial amounts of super-fine cobalt powder.

At present, there is the method much preparing cobalt powder both at home and abroad.As oxide, oxalates hydrogen reduction method, oxalates thermal decomposition Method, high-pressure water spray method, electrolysis, polyol process, microemulsion method, high pressure hydrogen reduction method, gas phase hydrogen reduction method, hydrazine liquid phase are also Former method etc..Some of which method has been carried out industrialization, and some are then also explored and development in laboratory.With the application of co powder The expansion in field, much old technique can not meet the requirement of powder property.It is domestic at present that hydrogen reduction method prepares cobalt powder A kind of commonly used technique, its production method is to produce satisfactory oxalic acid cobalt dust by chemical precipitation, then through hydrogen also Former produce cobalt powder, complex manufacturing, with low content of technology, prepared cobalt powder granularity is 1～3 micron, and particle size range is narrow and pattern For dendroid, spherical cobalt powder is few.

In some fields, such as hard alloy field, need that cobalt powder is spherical and granularity is more thin better, ultra-fine spherical cobalt Powder (fsss granularity be less than 1 micron) can be larger during producing low cobalt ultra-fine cemented carbide the wet grinding of shortening batch mixing when Between, and dispersibility in batch mixing for the ultra-fine spherical cobalt powder is better than with dendritic cobalt powder, its compound micro-area composition evenly, this Outward, ultra-fine spherical cobalt powder can even dispersion be distributed between carbide, from but Binder Phase is more evenly distributed in hard phase In, effectively compensate for during the typically dendritic cobalt powder ultra-fine hard alloy in low cobalt of production, because cobalt is low, cobalt distributed mutually is uneven producing The problems such as raw cobalt pond and micropore, improve the bending strength of alloy；And in some fields, such as military project cobalt powder field etc., need Want the cobalt powder that granularity is fsss3.9-4.5, to meet some specific demands.Therefore, the cobalt powder particle size range of prior art narrow and Pattern is dendroid, and suitable application area is restricted.

Content of the invention

It is an object of the invention to solving the deficiency that super-fine cobalt powder is prepared by prior art China, provide a kind of high pressure hydrogen reduction Prepare the method for cobalt powder so as to process is simple, loose specific weight be big and even particle size distribution, product cut size wide ranges, can be according to need Particle size range to be obtained is the cobalt powder of 0.4-4.5 micron.

Technical scheme

A kind of method that cobalt powder is prepared in high pressure hydrogen reduction: add dispersant toward in cobalt salt solution, be added to after mix homogeneously In reactor, toward in reactor, add ammonia, heat up after mixing, then pass to hydrogen and carry out hydrogenation reduction, reaction terminates Lower the temperature afterwards discharging, the product obtaining is filtered, after washing, then is vacuum dried, finally carry out pulverizing, sieve and obtain final product.With cobalt The weight meter of cobalt in saline solution, the dosage of described dispersant is 7-55ml/kg cobalt.

Further, described cobalt salt solution is cobaltous sulfate or cobalt chloride solution, and concentration is 30-120g/l.

Further, described dispersant is antisludging agent or poly- 2-butylene enuatrol, and described antisludging agent can be General Electric's water The trade mark that treatment technology company limited produces is the product of hypersperse mdc708.

Further, described ammonia dosage is with the mol ratio of ammonia and cobalt as 1.8-2.5molnh₃/ mol cobalt meter.

Further, described hydrogenation reduction controls at 140-220 DEG C, after hydrogenation Stress control in 2.0-3.8mpa, instead 30-200min between seasonable.

Further, in order to improve reactor effect, described hydrogenation reduction is the reaction carrying out under agitation, stirs Mix rate controlled in 200-600r/min.

Further, described vacuum drying Stress control bears 0.09mpa in negative 0.03-, and temperature control, at 70-150 DEG C, is dried Time 1-4h.

Further, relatively low in order to ensure cobalt powder oxygen content, gained cobalt powder wet feed filters, washs, dries, pulverizes, is sieving through Journey needs quick and is continuously finished, it is to avoid be exposed to air for a long time.

Beneficial effect: the inventive method process is simple, the cobalt powder granularity of preparation can reach 0.4-4.5 micron and particle diameter distribution Uniformly, there is larger loose specific weight and good mobility, every physical index and carbon oxygen content are all up to standard, and suitable application area is wide General.

Brief description

Fig. 1 is the sem figure that the cobalt powder that embodiment 1 is obtained amplifies 500 times；

Fig. 2 is the sem figure that the cobalt powder that embodiment 1 is obtained amplifies 1000 times；

Fig. 3 is the sem figure that the cobalt powder that embodiment 2 is obtained amplifies 500 times；

Fig. 4 is the sem figure that the cobalt powder that embodiment 2 is obtained amplifies 1000 times；

Fig. 5 is the sem figure that the cobalt powder that embodiment 3 is obtained amplifies 500 times；

Fig. 6 is the sem figure that the cobalt powder that embodiment 3 is obtained amplifies 1000 times；

Fig. 7 is the sem figure that the cobalt powder that embodiment 4 is obtained amplifies 500 times；

Fig. 8 is the sem figure that the cobalt powder that embodiment 4 is obtained amplifies 1000 times.

Specific embodiment

Embodiment 1

Poly- for 200ml 2-butylene enuatrol is added to 16.25l, in the cobalt sulfate solution of 120g/l, after stirring evenly, adds high pressure In reactor, then add 44.75l pure water in kettle.4l strong aqua ammonia is added in reactor.It is passed through nitrogen in reactor to arrive 1mpa about, then empty, replacement reaction kettle starts to stir and heat up twice afterwards, after being warming up to 210 DEG C, starts to be passed through hydrogen, pressure Power sets 3.0-3.5mpa, sustained response 1 hour about.Then cooling discharging, is vacuum dried after filter washing at 90 DEG C, Through crushing and screening the canescence cobalt powder of prepared good fluidity after drying, its electron microscope picture (sem) as shown in Figure 1, 2, from In figure can be seen that cobalt powder is spherical shape.

Embodiment 2

Poly- for 180ml 2-butylene enuatrol is added to 16.25l, in the cobalt chloride solution of 120g/l, after stirring evenly, is added to height In pressure reactor, then add 44.75l pure water in kettle.4l strong aqua ammonia is added in reactor.It is passed through nitrogen in reactor to arrive 1mpa about, then empty, replacement reaction kettle starts to stir and heat up twice afterwards, after being warming up to 200 DEG C, starts to be passed through hydrogen, pressure Power sets 3.0-3.5mpa, sustained response 1 hour about.Then cooling discharging, after filter washing, at 110 DEG C, vacuum is done Dry, through crushing and screening the canescence cobalt powder of prepared good fluidity after drying, its electron microscope picture (sem) as shown in Figure 3,4, Cobalt powder is spherical shape as can be seen from Figure.

Embodiment 3

150ml antisludging agent is added to 38l, in the cobalt sulfate solution of 120g/l, is added to after stirring evenly in autoclave, 17.7l pure water is added again in kettle.9.3l strong aqua ammonia is added in reactor.It is passed through nitrogen to 1mpa in reactor, Empty again, replacement reaction kettle starts to stir and heat up twice afterwards, after being warming up to 180 DEG C, start to be passed through hydrogen, pressure sets 3.0- 3.5mpa, sustained response 2 hours about.Then cooling discharging, is vacuum dried, warp after drying after filter washing at 110 DEG C Crush and screen the canescence cobalt powder of prepared good fluidity, its electron microscope picture (sem) as shown in Figure 5,6, can from figure Going out cobalt powder is spherical shape.

Embodiment 4

60ml antisludging agent is added to 50l, in the cobalt sulfate solution of 120g/l, is added to after stirring evenly in autoclave, 3l pure water is added again in kettle.12l strong aqua ammonia is added in reactor.It is passed through nitrogen to 1mpa in reactor, then arrange Sky, replacement reaction kettle starts to stir and heat up twice afterwards, after being warming up to 150 DEG C, starts to be passed through hydrogen, pressure sets 2.5- 3.0mpa, sustained response 3 hours about.Then cooling discharging, is vacuum dried, warp after drying after filter washing at 140 DEG C Crush and screen the canescence cobalt powder of prepared good fluidity, its electron microscope picture (sem) as shown in Figure 7,8, can from figure Going out cobalt powder is spherical shape.

Cobalt powder physical index obtained by test above-described embodiment, and the cobalt prepared with the hydrogen reduction method of domestic usual employing Powder carries out contrast test, and result see table:

Claims

1. a kind of high pressure hydrogen reduction prepares the method for cobalt powder it is characterised in that adding dispersant, mix homogeneously toward in cobalt salt solution After be added in reactor, toward in reactor add ammonia, after mixing heat up, then pass to hydrogen and carry out hydrogenation reduction, React discharging of lowering the temperature after terminating, after the product obtaining filtration, washing, then be vacuum dried, finally carry out pulverizing, sieve i.e. ?；

In terms of the weight of cobalt in cobalt salt solution, the dosage of described dispersant is 7-55ml/kg cobalt.

2. high pressure hydrogen reduction as claimed in claim 1 prepares the method for cobalt powder it is characterised in that described cobalt salt solution is sulphuric acid Cobalt or cobalt chloride solution, concentration is 30-120g/l.

3. high pressure hydrogen reduction as claimed in claim 1 prepares the method for cobalt powder it is characterised in that described dispersant is antisludging agent Or poly- 2-butylene enuatrol.

4. high pressure hydrogen reduction as claimed in claim 1 prepare cobalt powder method it is characterised in that described ammonia dosage with ammonia and The mol ratio of cobalt is 1.8-2.5molnh₃/ mol cobalt meter.

5. high pressure hydrogen reduction as claimed in claim 1 prepares the method for cobalt powder it is characterised in that described hydrogenation reduction control , at 140-220 DEG C, after hydrogenation, Stress control is in 2.0-3.8mpa, response time 30-200min for system.

6. high pressure hydrogen reduction as claimed in claim 1 prepares the method for cobalt powder it is characterised in that described hydrogenation reduction is The reaction carrying out under agitation, stir speed (S.S.) controls in 200-600r/min.

7. the high pressure hydrogen reduction as described in any one of claim 1 to 6 prepares the method for cobalt powder it is characterised in that described vacuum Drying pressure control negative 0.03- bear 0.09mpa, temperature control at 70-150 DEG C, drying time 1-4h.