Plating Solution Recovery Apparatus and Plating Solution Recovery Method

Abstract

A plating solution recovery apparatus for electroplating, the apparatus comprises a circulation tank; a sludge removing device; a concentrating device; an iron compound crystallizing device; an iron compound separating device; an iron compound redissolving device; an iron ion removing device; pipelines sequentially connecting the circulation tank, the sludge removing device, the concentrating device, the iron compound crystallizing device, the iron compound separating device, the iron compound redissolving device, and then the iron ion removing device in a downstream direction from a base point coincident with the circulation tank; a pipeline connecting from the iron ion removing device to the circulation tank; a pipeline connecting from the iron compound separating device to the circulation tank; and a flow path changing device connecting to the circulation tank and provided in at least one portion selected from a group of portions, respectively, between the sludge removing device and the concentrating device, between the concentrating device and iron compound crystallizing device, and between the iron compound crystallizing device and the iron compound separating device. With the apparatus being used, the plating solution can be recovered in the manner that sludge and iron are removed from the plating solution used for electroplating of a steel strip. Further, with the apparatus being used, even when stopping the operation of a device(s) related to iron removal, a continuous electroplating operation can be maintained without reducing the operation rate of the sludge removing device.

1 . A plating solution recovery apparatus for electroplating, comprising:
 a circulation tank;   a sludge removing device;   a concentrating device;   an iron compound crystallizing device;   an iron compound separating device;   an iron compound redissolving device;   an iron ion removing device;   pipelines sequentially connecting the circulation tank, the sludge removing device, the concentrating device, the iron compound crystallizing device, the iron compound separating device, the iron compound redissolving device, and then the iron ion removing device in a downstream direction from a base point coincident with the circulation tank;   a pipeline connecting from the iron ion removing device to the circulation tank;   a pipeline connecting from the iron compound separating device to the circulation tank; and   a flow path changing device connecting to the circulation tank and provided in at least one portion selected from a group of portions, respectively, between the sludge removing device and the concentrating device, between the concentrating device and iron compound crystallizing device, and between the iron compound crystallizing device and the iron compound separating device.   
   
   
       2 . A plating solution recovery apparatus as defined in  claim 1 , wherein the flow path changing device is provided in the portion between the sludge removing device and the concentrating device. 
   
   
       3 . A plating solution recovery apparatus as defined in  claim 1 , wherein the flow path changing device is provided in the portion between the concentrating device and the iron compound crystallizing device. 
   
   
       4 . A plating solution recovery apparatus as defined in  claim 1 , wherein the flow path changing device is provided in the portion between the iron compound crystallizing device and the iron compound separating device. 
   
   
       5 . A plating solution recovery apparatus as defined in  claim 1 , further comprising a flow path changing device connecting to the circulation tank and provided in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       6 . A plating solution recovery apparatus for enabling reuse of a plating solution used to apply electroplating onto a steel strip, the apparatus comprising:
 a circulation tank for storing the plating solution;   a sludge removing device for removing sludge in the plating solution supplied from the circulation tank;   a plating solution concentrating device for concentrating the plating solution supplied from the sludge removing device;   an iron precipitating device for precipitating an iron compound by cooling the plating solution supplied from the plating solution concentrating device;   an iron separating device for separating the iron compound from the plating solution supplied from the iron precipitating device and for redissolving the iron compound in water;   an iron removing device for removing an iron ion of a redissolved solution supplied from the iron separating device by means of an ion-exchange resin; and   a flow path changing device for supplying the plating solution from the plating solution concentrating device to the circulation tank.   
   
   
       7 . An operating method for the plating solution recovery apparatus as defined in  claim 1 , wherein, when stopping at least one device from a group consisting of the concentrating device, the iron compound crystallizing device, the iron compound separating device, the iron compound redissolving device, and the iron ion removing device, the flow path for the plating solution is changed to the circulation tank on a side further upstream of a most-upstream side stopped device and in the at least one portion selected from the group of portions, respectively, between the sludge removing device and the concentrating device, between the concentrating device and iron compound crystallizing device, and between the iron compound crystallizing device and the iron compound separating device. 
   
   
       8 . An operating method for the plating solution recovery apparatus as defined in  claim 1 , wherein, when stopping at least one device from a group consisting of the iron compound crystallizing device, the iron compound separating device, the iron compound redissolving device, and the iron ion removing device, the flow path for the plating solution is changed to the circulation tank on a side further upstream of a most-upstream side stopped device and in the at least one portion selected from the group of portions, respectively, between the sludge removing device and the concentrating device, between the concentrating device and iron compound crystallizing device, and between the iron compound crystallizing device and the iron compound separating device. 
   
   
       9 . An operating method for the plating solution recovery apparatus as defined in  claim 1 , wherein, when stopping at least one device from a group consisting of the iron compound separating device, the iron compound redissolving device, and the iron ion removing device, the flow path for the plating solution is changed to the circulation tank on a side further upstream of a most-upstream side stopped device and in the at least one portion selected from the group of portions, respectively, between the sludge removing device and the concentrating device, between the concentrating device and iron compound crystallizing device, and between the iron compound crystallizing device and the iron compound separating device. 
   
   
       10 . An operating method for the plating solution recovery apparatus as defined in  claim 5 , wherein, when stopping the iron ion removing device, the flow path for the redissolved solution is further changed to the circulation tank in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       11 . An operating method for the plating solution recovery apparatus, as defined in  claim 7 , wherein the electroplating solution contains tin methanesulfonate. 
   
   
       12 . A plating solution recovery method for enabling reuse of a plating solution used to apply electroplating onto a steel strip, wherein
 after the plating solution stored in a circulation tank is supplied to a sludge removing device and sludge in the plating solution is removed;   the plating solution is supplied to a plating solution concentrating device, and the plating solution is concentrated therein;   the plating solution is supplied to an iron precipitating device, and iron in the plating solution is precipitated therein as an iron compound;   the plating solution is supplied to an iron separating device, the iron compound is separated, and the separated iron compound is redissolved in water to be a redissolved solution;   the redissolved solution is supplied to an iron removing device, and an iron ion is removed therein by means of an ion-exchange resin; and   the plating solution from which the iron compound has been removed in the iron separating device and the redissolved solution from which the iron ion has been removed in the iron removing device are supplied to the circulation tank,   wherein, when stopping operation of the iron precipitating device, the iron separating device, or iron removing device, the plating solution is supplied from the plating solution concentrating device to the circulation tank.   
   
   
       13 . A plating solution recovery apparatus as defined in  claim 2 , further comprising a flow path changing device connecting to the circulation tank and provided in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       14 . A plating solution recovery apparatus as defined in  claim 3 , further comprising a flow path changing device connecting to the circulation tank and provided in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       15 . A plating solution recovery apparatus as defined in  claim 4 , further comprising a flow path changing device connecting to the circulation tank and provided in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       16 . An operating method for the plating solution recovery apparatus as defined in  claim 13 , wherein, when stopping the iron ion removing device, the flow path for the redissolved solution is further changed to the circulation tank in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       17 . An operating method for the plating solution recovery apparatus as defined in  claim 14 , wherein, when stopping the iron ion removing device, the flow path for the redissolved solution is further changed to the circulation tank in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       18 . An operating method for the plating solution recovery apparatus as defined in  claim 15 , wherein, when stopping the iron ion removing device, the flow path for the redissolved solution is further changed to the circulation tank in a portion between the iron compound redissolving device and the iron ion removing device. 
   
   
       19 . An operating method for the plating solution recovery apparatus, as defined in  claim 8 , wherein the electroplating solution contains tin methanesulfonate. 
   
   
       20 . An operating method for the plating solution recovery apparatus, as defined in  claim 9 , wherein the electroplating solution contains tin methanesulfonate.