Embodiment
The feature of the removing device of the rare earth impurities in nickel plating solution of the present utility model is, have: will the heating unit of the nickel plating solution heating of rare earth impurities be comprised, the cooling unit of the nickel plating solution cooling of the precipitate of separating out by utilizing the heating of described heating unit being comprised, being separated with from the nickel plating solution utilizing described cooling unit to cool and removing the separation removing unit of described precipitate.
In the utility model, rare earth impurities refers to following material, such as when nickel plating R-Fe-B base sintered magnet (R comprises more than at least one in the rare earth element of Y and necessarily comprises Nd), for being dissolved in the R component of plating solution, and owing to almost existing with ionic condition in plating solution, therefore direct filtration is collected very difficult.Removing device of the present utility model is necessary formation with heating unit, and plating solution is heated to make the rare earth impurities existed with ionic condition be separated out with the solid precipitate form that can trap by known separation removing unit such as such as strainers by described heating unit.In addition, removing device of the present utility model is to be separated removing unit and cooling unit is necessary formation, described separation removing unit by precipitation, filter above-mentioned precipitate be separated removing from plating solution, described cooling unit cools in order to the plating solution of the precipitate effectively carrying out this separation removing and utilize described heating unit heats by comprising and obtain.It should be noted that, removing device of the present utility model is when nickel electroplates described R-Fe-B base sintered magnet, be not limited to the removing of the R component being dissolved in plating solution, also can be applied to similarly in plating solution with the removing of rare earth impurities that ionic condition exists.
Form the heating unit of removing device of the present utility model, as long as can be heated to utilize the temperature being separated removing unit and making the rare earth impurities existed with ionic condition in plating solution separate out with the form of the precipitate that can trap, expect the unit with following structure, the Heating temperature of this plating solution can be adjusted according to the rare earth hetero quality in the composition of plating solution, amount, plating solution, required treatment time etc.
According to the experiment of the present inventor, as long as the heating of more than 60 DEG C usually can be carried out, then described precipitate can be separated out.In order to be effectively applied to technical scale further, expect the selected heating unit that the plating solution comprising rare earth impurities can be heated to more than 80 DEG C.There is the tendency that the removing efficiency (precipitation efficiency of precipitate) of the higher then rare earth impurities of described Heating temperature more improves, its upper limit there is no need to limit especially, but from the view point of operability, security, further from the impact etc. of the composition on plating solution, expect the boiling point being less than plating solution.
If plating solution is heated to more than boiling point, then water sharply evaporates from plating solution, and the composition forming plating solution is sharply separated out.The boiling point of plating solution changes according to composition, and the boiling point of such as watt bath reaches about 102 DEG C.
Visible, the boiling point of plating solution is risen by molar and rises, if therefore with the boiling point of water that is 100 DEG C control for the upper limit, then can tackle the impurity removing of the different plating solution of composition.
As the described concrete heating unit realizing heating, well heater, heat-up heat exchanger etc. can be adopted.By using such heating unit, the nickel plating solution comprising rare earth impurities is heated to more than 60 DEG C, be heated to the scope of 80 DEG C to 100 DEG C further, further expectation is heated to the scope of 90 DEG C to 95 DEG C, effectively can realize the removing of the rare earth impurities as target.
It should be noted that, for forming each component of removing device of the present utility model, need the material using thermotolerance high according to the scope (temperature of the plating solution caused by heating) of described heating, the therefore higher cost increase must causing device entirety of this temperature.Implement in described heating temperature range, the heating temperature range particularly expected, consequently contribute to the cost increase of restraining device.
In addition, in order to add described the precipitation hankering promoting precipitate, expecting to stir plating solution in a heated state, expecting to arrange the known agitator being attached to described heating unit.
Such as, adopt and can realize pneumatic blending, the rotation of stirring rake or the device of the formation of stirring that brings based on the circulation etc. of pump.
Expect that plating solution is after being heated to described temperature, frontly to cool in separation removing precipitate (rare earth impurities).Namely, not only the process of plating solution becomes miscellaneous, and if by the plating solution after heating directly by being separated the filter core of removing unit such as strainer, then likely the life-span of filter core becomes extremely short, or Filter Core Failure sometimes, thus the removing that the rare earth impurities of target efficiency cannot be reached.
In addition, if by the plating solution after heating after filtration (precipitate removing after), return plating coating groove when not cooling, the plating solution that then temperature is high is mixed into the plating solution in the plating process of the temperature before being in heating, and the liquid temperature of the plating solution in this plating process rises.Temperature before stopping plating process to make the liquid temperature of plating solution entirety return to heating, from the viewpoint of the efficiency of plating process also undesirably.
Therefore, form the cooling unit of removing device of the present utility model, consider as mentioned above on the impact being separated removing unit, after precipitate removing, return plating coating groove time impact on the plating solution in plating process, expect the unit for its cooling temperature can be adjusted, expect the unit selecting the temperature (temperature roughly the same with the temperature in plating process in fact) before can being cooled to heating.
As the described concrete cooling unit realizing cooling, cooling tube, heat exchanger for cooling etc. can be adopted.
It should be noted that, plating coating groove usually has according to the temperature-measuring results based on the plating solution temperature of thermometer and makes well heater automatically carry out the automatic regulation function of open and close, even if the cooled temperature of plating solution after the heating higher than heating before temperature or lower than heating before temperature when, as long as enter the temperature in the scope of the plating temperature of setting by this automatic regulation function, then no problem in practical.
Form the separation removing unit of removing device of the present utility model, the precipitate of being separated out by described heating unit can be separated and remove, expect the amount of the size according to precipitate, precipitate, to carry out the amount of the plating solution processed etc. selected, known strainer, subsider etc. can be used as concrete separation removing unit.
Removing device of the present utility model comprises the formation having described heating unit, cooling unit and be separated removing unit, in order to effectively shift plating solution between each unit, usually to be connected by pipe arrangement by each unit and integrated.In addition, in order to more successfully carry out the transfer of plating solution, being desirably in prescribed position (such as between each unit) and the buanch units such as pump are set.
Removing device of the present utility model can adopt following formation: described heating unit, cooling unit be separated removing unit further across heating unit and accumulate comprise the nickel plating solution of rare earth impurities stationary tank be connected.When connecting described stationary tank, first the plating solution comprising rare earth impurities in a large number after using for a long time can be transferred to described stationary tank from the plating coating groove plating process, then by the plating solution in this stationary tank in the mode illustrated before successively via heating unit, cooling unit be separated removing unit to carry out the removing process of rare earth impurities (precipitate).As required, except described stationary tank, by the stationary tank connection of accumulating via the plating solution (eliminating the plating solution of rare earth impurities) being separated removing unit is configured at separation removing unit, the plating solution eliminating rare earth impurities can be carried out the storage of necessary time thus in this stationary tank.
This formation can realize the effects such as following: even if by rare earth impurities removing process and after removing, also can not the plating solution in plating process be had any impact, and the temperature adjustment, composition adjustment etc. that eliminate the plating solution of rare earth impurities also easily can be carried out in described stationary tank.
In addition, removing device of the present utility model can adopt following formation: across described heating unit, accumulation is comprised the stationary tank of the nickel plating solution of rare earth impurities as plating coating groove, connect in the mode that the nickel plating solution utilizing described separation removing unit to eliminate described precipitate can be made to return described plating coating groove.By adopting this formation, the removing of the rare earth impurities in described plating solution can be carried out most effectively.That is, following steps can be carried out continuously: extract (transfer) plating solution → utilize heating unit heats plating solution → utilize cooling unit from the plating coating groove plating process and cool plating solution → utilizations and be separated removing unit and be separated removing (filtrations) precipitate (rare earth impurities) → shift (liquor charging) separation to plating coating groove to remove (filtration) plating solution of precipitate.
In described formation effectively: not only described plating coating groove, heating unit, cooling unit, separation removing unit are connected by pipe arrangement, but also connect will via the pipe arrangement being separated the plating solution of removing unit and returning plating coating groove.It should be noted that, utilize such device in order to process continuously, according to what illustrate above, expect to carry out as follows: when utilizing cooling unit to cool plating solution, the temperature before heating is cooled to by first utilizing the plating solution after heating unit heats, the change of plating condition can be suppressed thus, the character of the electroplated film obtained is not changed.
If use described device, then by carrying out the removing of rare earth impurities continuously, the increase of the rare earth impurities in plating process can be suppressed.Therefore the operations such as rare earth impurities are removed, without the need to stopping plating process without the need to resembling the formation that illustrates to remove after rare earth impurities adopts other stationary tank be transferred to by plating solution beyond plating coating groove above.
In addition, even if stop plating process as required with described continuous process and remove rare earth impurities after plating solution is transferred to other stationary tank, also inhibits the increase of rare earth impurities, therefore, it is possible to reduce its frequency, boost productivity, from but expect.
It should be noted that, when utilizing removing device of the present utility model to remove rare earth impurities, with regard to the concentration of plating solution, expect that the concentration (1 times) identical with the concentration of carrying out plating process is carried out.
Add hanker moisture evaporation thus the concentration of plating solution rise time, expect that supplementary suitable water is to keep concentration.
Rare earth impurities in the nickel plating solution of acid ~ neutrality that removing device of the present utility model can be applied to removing suitably.Watt bath, perchloride bath, muriate bath, thionamic acid bath etc. can be enumerated as nickel plating solution.
Removing device of the present utility model most suitably can be applied to watt bath.
As the liquid composition of watt bath, it can be prevailing bath composition.Can be applied to and such as comprise single nickel salt 200 ~ 320g/L, nickelous chloride 40 ~ 50g/L, boric acid 30 ~ 45g/L, as the gloss-imparting agent of additive, the composition of indenture preventing agent (ピ ッ ト prevents drug).
In order to effectively use removing device of the present utility model, expecting the composition being analyzed plating solution at any time by known analytical procedure (titrimetry etc.), carrying out the adjustment formed.
Such as, when watt bath, by titrimetry nickelous chloride, total nickel try to achieve single nickel salt, then analyze boric acid by titration.
Composition when composition and the plating process of the plating solution after the rare earth impurities removing obtained by removing device of the present utility model are started has almost no change, and therefore carries out rare earth impurities removing and change that the liquid of plating coating groove that causes forms is slight.
Therefore, also compositional analysis can be carried out to the composition regulation some cycles of the plating solution being in plating coating groove.Analytical cycle suitably sets according to the formation of plating coating groove, turnout.
Analyze as a result, not necessarily need when the composition of plating solution is in span of control to add, but single nickel salt, nickelous chloride, the boric acid of not enough amount to be added time not enough to plating solution, the composition of adjustment plating solution.
Plating solution is expected to be heated to plating temperature during interpolation.If temperature is low, the dissolving of the reagent added is slack-off, or does not dissolve.Then with nickelous carbonate, sulfuric acid adjustment pH, add known gloss-imparting agent, indenture preventing agent, carry out plating process.
For the plating condition of the plating solution used after application removing device of the present utility model, size, process number etc. according to used equipment, method for plating, plated application suitably set.
As an example, the plating condition when plating using described watt to bathe composition is bathed expects to be pH3.8 ~ 4.5, bath temperature 45 DEG C ~ 55 DEG C, current density 0.1 ~ 10A/dm
2.
Rack mode, cylinder mode is had as method for plating, suitably selected according to the size of plated application, treatment capacity.
As the stationary tank be connected with removing device of the present utility model and plating coating groove, as long as use and the handled composition of plating solution, the groove of the suitable material of temperature.In addition, by the container of material high for thermotolerance is used for plating coating groove, security can be improved.
Below, be described according to the concrete formation of Fig. 1 to removing device of the present utility model.In addition, Fig. 1 illustrates the formation that can realize the effect that removing device of the present utility model has most effectively, that is, illustrate above be connected with plating coating groove 4 and can the device of processed continuously typical formation, but the utility model is not limited to the formation of Fig. 1.
Plating coating groove 4 has not shown positive plate, negative electrode, well heater, stirrer, and plating solution is built bath, can carry out nickel plating.
The material of plating coating groove 4 depends on used plating solution, but expects for vinylchlorid (PVC) or heat-resisting vinylchlorid (PVC).
Plating solution flow direction is illustrated with arrow in figure.
The filtering system 20 of plating solution is the system arranged to filter the rubbish floated in plating solution etc., the object of the application's utility model cannot be reached, that is, to separate out being present in the rare earth impurities in plating solution with ionic condition with the form of precipitate and to be separated removing.
Filtering system 20 possesses valve 3, pump 2 and strainer 1, and plating solution presses the sequential flowing of plating coating groove 4 → valve 3 → pump 2 → strainer 1 → plating coating groove 4, as previously mentioned, filters the rubbish etc. floated in plating solution.
The rare earth impurities removing that impurity removing system 30 will be present in ionic condition in plating solution.
Impurity removing system 30 possesses: valve 5, the pump 6 as buanch unit, the heat-up heat exchanger 7 as heating unit, the heat exchanger for cooling 8 as cooling unit, the strainer 9 as separation removing unit and valve 10, plating solution presses the sequential flowing of plating coating groove 4 → valve 5 → pump 6 → heat-up heat exchanger 7 → heat exchanger for cooling 8 → strainer 9 → valve 10 → plating coating groove 4, filters and carry out separation removing after the rare earth impurities be dissolved in plating solution is separated out.
It should be noted that, when precipitate is separated removing from plating solution, also can replaces as the strainer being separated removing unit and subsider is set, only reclaim the supernatant liquor of the plating solution after making precipitate sedimentation continuously, precipitate is separated removing.
Now float on the precipitate of the trace of subsider, can after liquor charging (transfer) to plating coating groove, the filtering system 20 subsidiary by above-mentioned plating coating groove is separated removing completely.
In impurity removing system 30, the material of pipe arrangement plating coating groove 4, heat-up heat exchanger 7, each unit of heat exchanger for cooling 8, strainer 9 connected suitably sets according to the composition of plating solution, temperature, but due to connect heat-up heat exchanger 7 and heat exchanger for cooling 8 pipe arrangement in flow through the plating solution of high temperature, therefore expect the material using thermotolerance high.
The iron pipe etc. using PP, fluoro-resin coated is expected as the material that thermotolerance is high.
Heat-up heat exchanger 7 can use known heat exchanger, is not particularly limited, and electric heater, steam can be selected as thermal source.Use the heat exchanger of steam to be easy to the heating carrying out plating solution, from but expect.
For heat exchanger for cooling 8, also can use known heat exchanger.As the refrigeration agent for heat exchanger for cooling 8, for using the form of refrigerant gas, also cold water can be used.
For heat-up heat exchanger 7 and heat exchanger for cooling 8, the composition of material according to plating solution, the temperature that contact plating solution part are suitably selected, but expect the material such as stainless steel, titanium that selection erosion resistance is high.
The form of heat-up heat exchanger 7 and heat exchanger for cooling 8, ability, suitably set according to the amount (capacity of plating coating groove) will carrying out the plating solution of heating and cooling, the amount, plating condition etc. that will carry out the goods of plating process.
Such as, figure 1 illustrates the formation comprising 1 heat-up heat exchanger 7 and 1 heat exchanger for cooling 8, also can adopt 2 heat-up heat exchanger 7 configured in series, then by the formation of 2 heat exchanger for cooling 8 configured in series, or 1 heat-up heat exchanger 7 and 1 heat exchanger for cooling 8 are 1 group, by the formation that 2 groups are connected in parallel.
The flow of plating solution of flowing in impurity removing system 30, suitably sets according to the capacity (amount of plating solution) of the ability of heat-up heat exchanger 7 and heat exchanger for cooling 8, plating coating groove 4, plating condition, the amount etc. that will carry out the goods of plating process.Flow passes through the ability of used pump 6, the opening and closing amount of valve 5 adjusts.
In addition, as heating unit, also the heat-up heat exchanger 7 described in Component units replacement flooding heater in the groove of regulation can be adopted, in addition, as cooling unit, the Component units flooding the cooling tube of throw-in type in the groove of regulation also can be adopted to replace described heat exchanger for cooling 8.
Not only refer at this cooling tube and cool the unit of this plating solution by pipe by there being the device of refrigeration agent, cold water to drop in via the plating solution after heating unit, being the general name to the end cooled by Peltier (ペ Le チ ェ) effect etc. being dropped into the device making plating solution cool in described plating solution, mainly referring to and the cooling end forming cooling unit is dropped into the unit cooling plating solution in plating solution.
The place of (between plating coating groove 4 and heat-up heat exchanger 7) before in FIG buanch unit and pump 6 being arranged at heating unit and heat-up heat exchanger 7, but can also be configured between heating unit and heat-up heat exchanger 7 and cooling unit and heat exchanger for cooling 8 as required, heat exchanger for cooling 8 and being separated between removing unit and strainer 9 or after strainer 9.
Such as, as heating unit, cooling unit, when the cooling segment of well heater, water cooler being dropped into the container being configured at top opening, during as the subsider that separation removing unit use top is open, or when they are combined, in the transfer pathway of plating solution, there is opening portion in a large number, the pressure of the plating solution therefore risen by buanch unit is reduced.Therefore to be transferred to for the purpose of next unit, in order to make the pressure increase of temporarily-depressed plating solution, expect to arrange multiple buanch unit.
In addition, when the flow of the plating solution shifted between each unit is many, expects valve etc. to be arranged between above-mentioned each unit and adjust flow.
Above, describe and connect each unit with pipe arrangement, and adopt pump as the removing device of the formation of the buanch unit of plating solution, but the utility model is not limited to this formation.Such as, except plating coating groove, arrange that (plating coating groove is the highest with difference of height successively, be provided with that to be separated the groove of removing unit minimum and configure) be provided with heating unit groove, be provided with cooling unit groove, be provided with the groove being separated removing unit, thus, even if not necessarily connecting pipings, and do not adopt the buanch units such as pump that plating solution also can be made to shift via each unit.But, even if when such formation, in order to implement the continuous process of above-mentioned middle explanation, being also desirably in be provided with to be separated between the groove of removing unit and plating coating groove and being connected by buanch units such as pumps.
When realizing removing device of the present utility model, carry out the following experiment shown in experimental example 1 ~ 5 in advance, its effect has been confirmed.
Experimental example 1
By having single nickel salt 250g/L, nickelous chloride 50g/L, the composition of boric acid 45g/L, the plating solution of pH4.5 be heated to 50 DEG C, implements nickel plating on the surface of R-Fe-B base sintered magnet.R-Fe-B base sintered magnet magnetic properties is as required used in the multiple magnet of adjustment composition in following scope, i.e. Nd:15 ~ 25mass%, Pr:4 ~ 7mass%, Dy:0 ~ 10mass%, B:0.6mass% ~ 1.8mass%, Al:0.07 ~ 1.2mass%, surplus is Cu, Ga of Fe, below 3mass%.But the composition of the magnet used in a lot is identical composition.
It should be noted that, be dissolved in respective composition, the amount of the rare earth impurities of plating solution, according to the combination of the magnet for plating, the treatment process of cylinder plating or tooth bar plating and so on, the composition of plating solution and different.
After carrying out the plating process of a few days, ICP apparatus for analyzing luminosity is utilized to analyze Nd impurity, Pr impurity, the Dy impurity of nickel plating solution.
Analytical results is Nd:500ppm, Pr:179ppm, Dy:29ppm.
The plating solution comprising described rare earth impurities is taken in a certain amount of (3 liters) beaker, keeps certain hour with well heater with the state being heated to 90 DEG C.In addition, hanker utilizing magnet-type stirrer (magnetic stirring apparatus) to stir adding.Hanker make up water to make the constant concentration of plating solution adding.
Stop heat and after cooling, getting the plating solution measured fully ICP luminescence analysis respectively after 24 hours and after 96 hours, the concentration of Nd, Pr, Dy of comprising in the plating solution after utilizing ICP apparatus for analyzing luminosity mensuration to utilize filter paper filtering.
Analytical results after 24 hours is Nd:100ppm, Pr:35ppm, Dy:16ppm.
Analytical results after 96 hours is Nd:50ppm, Pr:16ppm, Dy:2ppm.
As mentioned above, the rare earth impurities being dissolved in the ionic condition in nickel plating solution is heated as precipitate by the specified time, by utilizing the filtration of filter paper, being separated with plating solution, being removed.Even if also do not become the rare earth impurities of precipitate by the heating of specified time, ionic condition is kept to residue in plating solution with the ratio shown in described analytical results.Can be clear and definite from above-mentioned analytical results, heat-up time, the longer then amount of rare earth impurities that is separated with the form of precipitate, removing was more, and the amount being in the rare earth impurities of ionic condition consequently in plating solution reduces.
The treatment process of example 1 is known by experiment, and the impurity level as the Nd of rare earth element reduces, and the impurity level of Pr and Dy also reduces simultaneously.
Experimental example 2
By having single nickel salt 250g/L, nickelous chloride 50g/L, the composition of boric acid 45g/L, the plating solution of pH4.5 be heated to 50 DEG C, implements nickel electroplate on the surface of R-Fe-B base sintered magnet (using the magnet of the compositing range identical with embodiment 1).After carrying out a few days plating process, analyzing the Nd impurity in nickel plating solution, is 576ppm.
Heating temperature is set as from 6 conditions of 50 DEG C to 95 DEG C (wherein 50 DEG C to 90 DEG C, and 10 DEG C have 5 conditions for increment), to be taken to by described plating solution in the beaker of 3 liters and to heat in each condition.Hanker utilizing magnet-type stirrer (magnetic stirring apparatus) to stir adding.Hanker make up water to make the constant concentration of plating solution adding.And get the plating solution that ICP luminescence analysis is measured fully at every certain hour, the plating solution got is cooled and with after filter paper filtering, analyzes the content (concentration) of the Nd impurity in this plating solution.ICP apparatus for analyzing luminosity is used in analysis.
Analytical results to be shown in Table 1 and (results by 50 DEG C to 90 DEG C) are illustrated in the figure of Fig. 2.
[table 1]
Unit ppm
When Heating temperature is 50 DEG C, be 518ppm through 168 hours rear impurity concentration.When 60 DEG C, after 24 hours, impurity concentration reduces, and is 177ppm after 216 hours.70 DEG C compared with 60 DEG C, the trend that impurity concentration reduces when demonstrating normal in 24 hours later.
When Heating temperature is 80 DEG C, impurity concentration reduces from after just heating, is 125ppm after 96 hours.
When Heating temperature is 90 DEG C, be 134ppm after 24 hours, be 84ppm after 48 hours, is 59ppm after 96 hours.When Heating temperature is 95 DEG C, analyze after 24 hours and after 96 hours.Nd impurity level is roughly the same with situation about heating at 90 DEG C.
Can be clear and definite by above result, be can confirm clear and definite effect in the of 60 DEG C from Heating temperature, can also confirm 80 DEG C, remarkable all the more 90 DEG C of these effects further.
Experimental example 3
By the rear filter paper filtering of plating solution cooling after heat treated in experimental example 1 and experimental example 2, reclaim the precipitate of separating out from plating solution.
With the dry described precipitate of thermostatic bath.Proterties is powder (solid).
Energy dispersion type x-ray analysis equipment (EDX) is utilized to analyze precipitate, as follows:
Nd:32.532、Pr:11.967、Dy:1.581、Al:0.402、Ni:7.986、C:0.319、O:45.213(mass%)。
The rare earth impurities confirmed in plating solution is separated out from plating solution with the form of powder (solid) by heat treated.
Experimental example 4
By having single nickel salt 250g/L, nickelous chloride 50g/L, the composition of boric acid 45g/L, the plating solution of pH4.5 be heated to 50 DEG C, implements nickel electroplate on the surface of R-Fe-B base sintered magnet (using the magnet of the compositing range identical with embodiment 1).After carrying out a few days plating process, analyzing the Nd impurity in nickel plating solution, is 581ppm.
Described plating solution is taken in the beaker of 3 liters, heats at 90 DEG C.
Hanker utilizing magnet-type stirrer (magnetic stirring apparatus) to stir adding.Hanker make up water to make the constant concentration of plating solution adding, analyzed the content (concentration) of the Nd impurity in its plating solution simultaneously at 1,3,6,12,24 hour in the same manner as experimental example 1.
Analytical results is shown in Table 2 and is shown in the coordinate diagram of Fig. 3.
[table 2]
Unit ppm
? |
0hr |
1hr |
3hr |
6hr |
12hr |
24hr |
90℃ |
581 |
578 |
521 |
425 |
318 |
195 |
Hanker confirming 90 DEG C add, rear 3 hours of heating play Nd impurity significantly to be reduced.
Experimental example 5
To once the dissolving again of rare earth impurities of separating out is studied.
By having single nickel salt 250g/L, nickelous chloride 50g/L, the composition of boric acid 45g/L, the plating solution of pH4.5 be heated to 50 DEG C, implements nickel electroplate on the surface of R-Fe-B base sintered magnet (using the magnet of the compositing range identical with embodiment 1).After carrying out a few days plating process, analyzing the Nd impurity in nickel plating solution, is 544ppm.Described plating solution is taken in the beaker of 3 liters, is heated to 90 DEG C.
Hanker utilizing magnet-type stirrer (magnetic stirring apparatus) to stir adding.Hanker make up water to make the constant concentration of plating solution adding.After certain hour, get the plating solution that ICP luminescence analysis is measured fully, the plating solution got is cooled and with after filter paper filtering, analyzes the content (concentration) of the Nd impurity in this plating solution.ICP apparatus for analyzing luminosity is used in analysis.
In addition, below illustrate get plating solution after plating solution is cooled to 40 DEG C and be held in 40 DEG C time analytical results.
After being held in 40 DEG C, got at 1,3,6,24,48 hour the plating solution that ICP luminescence analysis is measured fully, filter the content (concentration) of the Nd impurity in this plating solution of post analysis.
Analytical results is shown in Table 3.
[table 3]
Unit ppm
Elapsed time |
0hr |
1hr |
3hr |
6hr |
24hr |
48hr |
Nd impurity |
122 |
121 |
115 |
116 |
125 |
121 |
0hr is the analytical value at 90 DEG C of plating solutions got.Even if the rare earth impurities confirming to utilize the method for above-mentioned explanation to separate out also no longer dissolves below the temperature of carrying out plating process, the impurity concentration in plating solution does not rise.
According to above experimental example, the Heating temperature expected is described.
From the result of experimental example 2, when keeping heated condition more than 60 DEG C, in plating solution after filtration, the amount of Nd impurity reduces, and in addition, the higher reduction effect of Heating temperature more improves.
The relation that the amount of Nd impurity and the dual plating of electroplated film, stripping occur changes according to plating condition, if the amount of Nd impurity is about 200ppm, can't see their generation.
When 1 week (168 hours) are carried out in the removing of Nd impurity, be reduced to about 200ppm when Heating temperature is 60 DEG C.Same confirmation is carried out 5 days (120 hours) when 70 DEG C, carries out 3 days (72 hours) when 80 DEG C, carries out the effect that 24 hours (1 day) can obtain roughly the same degree when 90 DEG C and 95 DEG C.
Visible, the time required for impurity reduces changes according to the Heating temperature of plating solution.
Using 1 week as during the unit produced time, keep within 168 hours, then filtering the plating solution obtained and can performing well in plating process at 60 DEG C, carrying out can being reduced to for 5 days at 70 DEG C in addition can the impurity level of plating.Similarly can reduce the impurity in plating solution with the shorter time at 80 DEG C, 90 DEG C, 95 DEG C.
If be the experimental example 4 of less than 24 hours with reference to research heat-up time, then known when being heated to 90 DEG C, the precipitation of impurity started in the moment through 3 hours, was about the impurity reducing amount of 10%.Impurity can be removed by the filtration of this precipitate.
Thus can prediction, the precipitation of rare earth impurities starts at short notice along with Heating temperature increases.Therefore, separating out rare earth impurities by the plating solution comprising rare earth impurities being heated to proper temperature with heat-up heat exchanger etc., then by cooling, filtration, from plating solution, effectively can remove rare earth impurities.If the result of reference experiment example 2, then confirm to hanker reducing about 35% at 24 hours impurity levels 80 DEG C add, if select more than 80 DEG C as Heating temperature, then can separate out impurity with the short period of time, more effectively can remove impurity.
In addition from the result of experimental example 5, even if the temperature of plating solution is reduced to below plating treatment temp, once the precipitate of separating out also no longer is dissolved in plating solution, therefore the plating solution of the precipitate comprised by adding heat evolution is cooled to the temperature before heating (carrying out the temperature of plating process), then filter, do not need temperature to adjust when the plating solution after filtration is returned plating coating groove thus.Therefore, plating process can not be stopped, implementing the impurity removing in plating solution continuously, in plant-scale production, the plating process of the plating overlay film that effectively can form stable character can be provided.
In above experimental example, confirm the reduction effect of Nd, Pr, Dy impurity, also can reduce Tb and other rare earth impurities.
Further, also can reduce the Fe impurity in plating solution, Cu impurity.
Embodiment
According to described experimental example, selected plating coating groove, heating unit, cooling unit, separation removing unit and buanch unit, make device of the present utility model.
It should be noted that, each unit wishes forming removing device of the present utility model has thermotolerance, and the part at least directly contacting plating solution has acid resistance (or alkali resistance).According to the formation represented in Fig. 1, an embodiment of removing device of the present utility model is described.In addition, comprise plating coating groove in the concrete function of interior each unit, operation as previously described, omit below.
Plating coating groove: for carrying out the plating coating groove 4 of nickel plating, material is by PVC(vinylchlorid) form.Plating solution uses watt bath.Plating temperature is 50 DEG C.
Heating unit: use heat exchanger as heating unit 7.Thermal source is used in the steam produced in not shown boiler, and the material of the part (portion in contact with the electrolyte) that plating solution passes through is titanium.
During removing rare earth impurities, with this heating unit, plating solution is heated to 90 DEG C, keeps certain hour.
Cooling unit: use heat exchanger as cooling unit 8.Cool known refrigeration agent with refrigerator, the nickel plating solution heated with described heat-up heat exchanger is cooled to 50 DEG C.Plating solution is titanium by the material of part (portion in contact with the electrolyte).
Be separated removing unit: as separation removing unit 9, with the known strainer using line winded filtering core (yarn volume Off イ Le タ).
Buanch unit: as the pump 4 shifted from plating coating groove 4 by plating solution, considers that acid resistance then at least contacts the part use resin-made material of plating solution.
Connector element: connect described heating unit 7, cooling unit 8 and the pipe arrangement being separated removing unit 9, and the pipe arrangement connecting separation removing unit 9 and plating coating groove 4 is heat-resistant polyvinyl chloride.
In addition, by the valve 5 in figure and valve 10, the flow shifting the plating solution of (liquor charging) to heating unit 7, cooling unit 8, separation removing unit 9 and plating coating groove 4 is regulated.
The condition surface to R-Fe-B base sintered magnet identical with experimental example 1 is utilized to carry out nickel plating, and the removing of rare earth impurities is carried out by described device, confirm to realize the removing with the rare earth impurities of experimental example 1 same degree, the increase of the rare earth impurities in the plating solution in plating process can be suppressed in fact.
Utilizability in industry
The utility model effectively can remove and be dissolved in plating solution when plating rare-earth magnet and rare earth impurities in the nickel plating solution causing so-called plating bad, has the utilizability in industry.
Nomenclature
1,9 strainers
2,6 pumps
3,5,10 valves
7 heat-up heat exchanger
8 heat exchanger for coolings
20 plating solution filtering systems
30 plating solution impurity removing systems