JP2018154544A - Chlorine-containing powder treating method and chlorine-containing powder treating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chlorine-containing powder treating method which can selectively elute chlorine from chlorine-containing powder and then remove the chlorine.SOLUTION: A chlorine-containing powder treating method includes: a slurring step of adding water to chlorine-containing powder and slurring the chlorine-containing powder; an ORP adjusting step of adjusting an oxidation reduction potential of slurry, for a relation of pH of the slurry and oxidation-reduction potential thereof to meet a predetermined formula; an elution step of eluting chlorine contained in the slurry which is adjusted, into water; and a dehydration step of dehydrating the slurry from which chlorine are eluted.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a treatment method and a treatment system for desalinating chlorine-containing powder and using it as a cement raw material.

  In the recycling process of waste due to the use of cement as a raw material, waste containing volatile components such as chlorine may cause problems such as blockage of cement production facilities due to the chlorine and the like. Therefore, in order to use chlorine-containing powder, for example, incineration ash or the like as a raw material for cement, it is used after reducing the amount of chlorine contained in the incineration ash by desalting.

  Regarding demineralization treatment of incineration ash and the like, for example, Patent Document 1 discloses a method of adding water to incineration ash to elute chlorine and then dehydrating, and Patent Document 2 includes water and acid in the incineration ash. The method of adding and dehydrating after eluting chlorine as a slurry having a pH of 6 to 10 is disclosed in Patent Document 3, in which the incinerated ash is washed multiple times by repeating mixing with water and dewatering to desalinate. However, in Patent Document 4, after the incineration ash is classified into coarse and fine particles, the coarse particles are washed with water, and the fine particles are washed with water and washed with water while being dispersed or crushed chemically or physically. Patent Document 5 discloses a method of desalting, after classifying the incinerated ash into coarse and fine particles, washing the coarse particles with water, and desalting the fine particles as a slurry having a pH of 3 to 10.5. A method is disclosed.

JP 2002-338312 A JP-A-10-202226 Japanese Patent Laid-Open No. 2003-211129 JP 2009-090173 A JP 2012-254456 A

  However, in the desalination treatment of chlorine-containing powder such as incinerated ash, if heavy metals are eluted together with chlorine, appropriate treatment for such heavy metals is required as an environmental measure. Therefore, a method of selectively eluting chlorine without eluting heavy metals as much as possible is desired. However, in this respect, it has been difficult to realize sufficiently selective elution of chlorine with the conventional method.

  The present invention has been made in view of the above points, a chlorine-containing powder treatment method capable of selectively eluting and removing chlorine from chlorine-containing powder such as incineration ash, and chlorine-containing powder. An object is to provide a processing system.

In order to achieve the above object, the chlorine-containing powder treatment method of the present invention includes a slurrying step in which at least water is added to the chlorine-containing powder to form a slurry, and the pH and oxidation-reduction potential of the slurry (hereinafter, ORP adjustment step of adjusting the oxidation-reduction potential of the slurry so that the relationship of “ORP” may satisfy both the following formula (1) and the following formula (2); And an elution step of eluting chlorine contained in the chlorine-containing powder in the slurry in the slurry, and a dehydration step of dehydrating the slurry from which the chlorine was eluted to obtain a cement raw material. It is characterized by being.
(ORP (mV)) ≦ −150 × (pH) +1400 (1)
(ORP (mV)) ≦ 40 × (pH) −320 (2)
(However, in both formulas (1) and (2), the pH range is 3 ≦ pH ≦ 12.)

  Thus, in the chlorine-containing powder processing method of the present invention, when chlorine is eluted from the slurry-containing chlorine-containing powder, the relationship between the pH of the slurry and the ORP is expressed by the formula (1) and the formula ( The ORP is adjusted to satisfy both of 2). Thereby, eluting of heavy metals can be avoided and chlorine can be selectively eluted and removed. On the other hand, when the relationship between the pH of the slurry and the ORP does not satisfy either of the formula (1) or the formula (2), elution of heavy metals cannot be sufficiently avoided from the chlorine-containing powder. Normally, the pH of the slurry due to incineration ash and the like falls within the range of 3 to 12, so it is not particularly necessary to adjust the pH of the slurry, but in the unlikely event that the pH does not fall within the above range, Adjust the ORP so that both the above formula (1) and the above formula (2) are satisfied after adjusting the pH within the above range using an appropriate pH adjusting agent (sulfuric acid, sodium hydroxide, etc.) Good.

In the ORP adjustment step, the relationship between the pH of the slurry and the oxidation-reduction potential (ORP) satisfies the following formula (3) in addition to both the formula (1) and the formula (2). Thus, the oxidation-reduction potential of the slurry may be adjusted. According to this, there is no excessive cost for the use of a medicine or the like for ORP adjustment.
(ORP (mV)) ≧ −600 (3)

  Further, the chlorine-containing powder processing method of the present invention comprises an ORP measurement step for measuring the oxidation-reduction potential of the slurry obtained in the slurrying step, and the relationship between the pH of the slurry and the oxidation-reduction potential is When either of the formula (1) and the formula (2) is not satisfied, an ORP regulator is added to the slurry in the ORP adjustment step to change the oxidation-reduction potential of the slurry to the formula (1) and the formula (1). You may make it adjust so that both Formula (2) may be satisfied.

  Moreover, in the processing method of the chlorine containing powder of this invention, it is preferable that the said ORP regulator is sodium hydrogen sulfide (sodium hydrosulfide).

  Moreover, in the processing method of the chlorine containing powder of this invention, you may make it reuse the waste_water | drain collect | recovered at the said dehydration process at the said slurrying process, the said ORP adjustment process, and the said elution process.

  Moreover, in the processing method of the chlorine containing powder of this invention, it is preferable that the temperature of the said slurry shall be 5-50 degreeC at the said elution process. When the temperature of the slurry during elution is within the above range, chlorine can be efficiently eluted.

In order to achieve the above object, the chlorine-containing powder processing system of the present invention comprises a powder dissolution / reaction tank for making a stored chlorine-containing powder into a slurry, and the powder dissolution / reaction tank. An ORP adjusting device for adjusting the oxidation-reduction potential of the slurry so that the relationship between pH and ORP of the slurry contained in the slurry satisfies both the following formula (1) and the following formula (2): A solid-liquid separation device for solid-liquid separation of the slurry discharged from the dissolution / reaction tank is provided.
(ORP (mV)) ≦ −150 × (pH) +1400 (1)
(ORP (mV)) ≦ 40 × (pH) −320 (2)
(However, in both formulas (1) and (2), the pH range is 3 ≦ pH ≦ 12.)

  As described above, in the chlorine-containing powder processing system of the present invention, the chlorine-containing powder is contained in a powder dissolution / reaction vessel to form a slurry, and when chlorine is eluted from the slurry, The ORP is adjusted so that the relationship between the pH and the ORP satisfies both the formula (1) and the formula (2). Thereby, eluting of heavy metals can be avoided and chlorine can be selectively eluted and removed. On the other hand, when the relationship between the pH of the slurry and the ORP does not satisfy either of the formula (1) or the formula (2), elution of heavy metals cannot be sufficiently avoided from the chlorine-containing powder. In addition, as mentioned above, since the pH of the slurry by incineration ash etc. usually falls within the range of 3 to 12, the pH adjustment of the slurry is not particularly necessary, but in the unlikely event that the pH does not fall within the above range In order to satisfy both the formula (1) and the formula (2), the pH is adjusted to fall within the above range using an appropriate pH adjuster (sulfuric acid, sodium hydroxide, etc.). The ORP may be adjusted.

In the ORP adjusting device, the relationship between the pH of the slurry accommodated in the powder dissolution / reaction vessel and the oxidation-reduction potential (ORP) is added to both the formula (1) and the formula (2). Furthermore, the oxidation-reduction potential of the slurry may be adjusted so that the following formula (3) is also satisfied. According to this, there is no excessive cost for the use of a medicine or the like for ORP adjustment.
(ORP (mV)) ≧ −600 (3)

  In the chlorine-containing powder processing system of the present invention, the ORP measuring device that measures the oxidation-reduction potential of the slurry generated in the powder dissolution / reaction vessel, and the measurement result of the ORP measuring device, It is preferable to include a control device that automatically controls the ORP adjustment device. As described above, when the ORP is automatically measured and managed, the chlorine-containing powder can be more stably processed. Note that the pH of the slurry does not vary greatly in the slurrying process, the ORP adjustment process, and the elution process, so the initial measurement value may be fixed without performing continuous measurement.

BRIEF DESCRIPTION OF THE DRAWINGS It is schematic structure explanatory drawing which shows one Embodiment of the processing system of the chlorine containing powder which concerns on this invention. It is a flowchart explaining the process performed in the processing system shown in FIG. It is a relationship diagram of pH and redox potential (ORP) showing the applicable range of the present invention.

  Hereinafter, a chlorine-containing powder processing system according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of a chlorine-containing powder processing system according to the present invention. The chlorine-containing powder processing system 1 (hereinafter referred to as “processing system 1”) of this embodiment includes a powder dissolution / reaction tank 2 that generates slurry S, and an ORP regulator in the powder dissolution / reaction tank 2. A chemical addition device 3 for supplying A1, a solid-liquid separation device 4 for solid-liquid separation of the slurry S discharged from the powder dissolution / reaction tank 2, and a solid phase (dehydrated cake) discharged from the solid-liquid separation device 4 Is provided with a dehydrating cake transporting device 5 for transporting the raw material to the cement manufacturing facility K, and a control device 6 for controlling the various devices attached to the powder dissolution / reaction tank 2 and the chemical addition device 3.

  In the powder dissolution / reaction tank 2, the chlorine-containing powder P, the water W 1, and the ORP regulator A 1 are mixed therein to produce a slurry S, and the chlorine-containing powder in the slurry S A treatment for eluting chlorine into the liquid phase is performed.

  In addition, the powder dissolution / reaction vessel 2 has a slurry agitation for mixing the chlorine-containing powder P, water W1, and ORP regulator A1, and for agitation of the slurry S generated by the mixing. As a device, a stirring blade 21 is attached. As the stirring blade 21, for example, a general screw-type blade may be used.

  In addition, the powder dissolution / reaction vessel 2 has a thermometer 22 for measuring the temperature of the slurry S generated therein, and an ORP meter 23 (ORP measuring device) for continuously measuring the ORP of the slurry S. It is attached. And the measurement result of the thermometer 22 and the ORP meter 23 is transmitted to the control apparatus 6 at any time. Further, the powder dissolution / reaction tank 2 may be provided with a pH meter (pH measurement device), and the measurement result may be transmitted to the control device 6.

  For example, a known thermometer may be used as the thermometer 22. As the ORP meter 23, a known measuring device may be used, and it is particularly preferable to use a measuring device for high concentration suspension. In addition, when attaching a pH meter (pH measuring device), as the pH meter and the ORP meter 23, a composite device in which they are integrated may be used.

  Furthermore, in the powder dissolution / reaction vessel 2 of this embodiment, a heating facility 24 is attached to the inside thereof, and the temperature of the slurry S measured by the thermometer 22 can be controlled by the heating facility 24. I am doing so. As the heating equipment 24, for example, a device that supplies a high temperature gas G1 such as exhaust gas into the slurry S using an air diffuser, a general low frequency induction heating device, or the like may be used.

  As the high temperature gas G1, for example, carbon dioxide gas such as high temperature exhaust gas from the cement production facility K is preferably used. By using carbon dioxide gas, the pH of the slurry S changes to the acidic side, but the calcium ions eluted in the liquid phase of the slurry S are separated into solid and liquid by the solid-liquid separation device 4 described later, It can be recovered in the solid phase. Thereby, in the waste water W2 separated in the dehydration process described later, an effect of suppressing the generation of scale (gypsum) due to the calcium ions eluted in the liquid phase forming salts with sulfate ions and the like is brought about. Thus, from the viewpoint of suppressing the generation of scale, the pH of the slurry S is preferably 7-11.

  The chemical addition device 3 supplies the ORP adjusting agent A1 to the powder dissolution / reaction vessel 2 based on a signal from the control device 6. That is, in the processing system 1, the ORP of the slurry S generated in the powder dissolution / reaction tank 2 is adjusted by the ORP adjusting agent A <b> 1 supplied from the chemical addition device 3. Therefore, in this embodiment, it can be considered that the medicine addition device 3 constitutes an ORP adjustment device.

  Slurry S discharged from the powder dissolution / reaction vessel 2 is conveyed to the solid-liquid separator 4 by a normal slurry liquid transport device (not shown) such as a slurry centrifugal pump, piston pump, and Mono pump. The As the solid-liquid separation device 4, a normal filtration device such as a filter press, a pressurized leaf filtration device, a screw press, or a belt press may be used.

  The solid-liquid separation device 4 is configured to remove the transported slurry S from waste water W2 (liquid phase) containing chlorine eluted from the chlorine-containing powder P and dehydrated cake C (solid phase) made of the powder from which chlorine is eluted. And to separate. In the processing system 1, the water-washing device 4 a for the dehydrated cake C is provided in the solid-liquid separation device 4 in order to ensure recovery of the eluted components. However, this water cleaning device 4a may be omitted.

  The dehydrated cake transport device 5 transports the dehydrated cake C separated from the slurry S by the solid-liquid separator 4 to the cement manufacturing facility K. As the dehydrated cake transport device 5, for example, a general cake transport device such as a belt conveyor, a screw conveyor, or a pipe conveyor may be used.

  In the processing system 1 shown in this embodiment, the control device 6 adjusts the temperature of the powder dissolution / reaction vessel 2 and the ORP adjustment based on the measurement results of the thermometer 22 and the ORP meter 23 and the input value or measurement result of pH. The supply amount of the agent A1 is automatically controlled. Thereby, more stable processing can be performed regardless of the type of the chlorine-containing powder P.

  Next, processing performed in the processing system 1 will be described with reference to FIG. 2 together with FIG.

  First, in the powder dissolution / reaction tank 2, the stirring blade 21 stirs the chlorine-containing powder P and the water W1 to create a slurry S (STEP 01 in FIG. 2) (slurry process). The mixing ratio of the chlorine-containing powder P and the water W1 in the slurry S may be appropriately set depending on the type of the chlorine-containing powder P. However, when the chlorine-containing powder P: water W1 = 1: 4 to 1:20, and preferably the chlorine-containing powder P: water W1 = 1: 5 to 1:10, the amount of water W1 used is suppressed. , Chlorine can be sufficiently removed.

  Next, the ORP meter 23 measures the oxidation-reduction potential (ORP) of the slurry S (STEP02 in FIG. 2) (ORP measurement step), transmits the measurement result to the control device 6, and receives the measurement result. The apparatus 6 determines whether or not the relationship between the pH of the slurry S and the oxidation-reduction potential (ORP) satisfies both the formula (1) and the formula (2) (STEP 03 in FIG. 2). The pH value of the slurry may be measured by placing a pH meter (not shown) in the powder dissolution / reaction vessel 2 and transmitting the measurement result to the control device 6. In addition, continuous measurement and transmission may be performed. However, since a large fluctuation is not usually generated in the pH of the slurry, the measurement value immediately after the slurry S is homogenized is not performed without performing continuous measurement. 6 may be input at least once. Alternatively, a predetermined initial value arbitrarily set based on the type of the chlorine-containing powder P may be fixed and used. Normally, the pH of the slurry due to incineration ash and the like falls within the range of 3 to 12, so it is not particularly necessary to adjust the pH of the slurry, but in the unlikely event that the pH does not fall within the above range, If it is determined whether or not both the formula (1) and the formula (2) are satisfied after adjusting the pH to be within the above range using an appropriate pH adjuster (sulfuric acid, sodium hydroxide, etc.) Good.

  When the relationship between the pH of the slurry S and the oxidation-reduction potential (ORP) does not satisfy either of the formula (1) or the formula (2) (NO in STEP03 of FIG. 2), the control device 6 By adjusting the redox potential (ORP) of the slurry S by adding the ORP adjusting agent A1 via the chemical addition device 3 by the control based on the signal of (2) (step 04 in FIG. 2) (ORP adjustment) Process). As the ORP adjusting agent A1 used in the ORP adjusting step, for example, sodium hydrogen sulfide may be used.

  When slurry S is produced using general incineration ash or the like as general chlorine-containing powder P without using ORP regulator A1, its redox potential (ORP) is about −20 mV, Since the pH is about 12, it is usually necessary to add at least the ORP regulator A1.

  If the relationship between the pH of the slurry S and the oxidation-reduction potential (ORP) satisfies both the formula (1) and the formula (2) (in the case of YES in STEP 03 in FIG. 2), the slurry S is selected. Although chlorine can be eluted, it is preferable that the oxidation-reduction potential (ORP) of the slurry S is not excessively lowered from the viewpoint of the use cost of the ORP regulator A1. For example, the lower limit of ORP is preferably about −600 mV, more preferably about −500 mV, and particularly preferably about −450 mV.

  The measurement of the oxidation-reduction potential (ORP) of the slurry S so that the relationship between the pH of the slurry S and the oxidation-reduction potential (ORP) is maintained in a range satisfying both the formula (1) and the formula (2). While the adjustment is continuously repeated until the predetermined stirring time of the slurry S is reached, stirring of the slurry S is continued to elute chlorine into the liquid phase (STEP 05 in FIG. 2) (elution step).

  In order to promote the elution of chlorine, the stirring time required for the elution of chlorine is preferably 30 minutes or more, and particularly preferably 45 minutes or more.

  In the chlorine elution step, the control device 6 controls the heating equipment 24 based on the signal from the thermometer 22 to maintain the temperature of the slurry S at a predetermined temperature. This is to further promote the elution of chlorine. The temperature is preferably 5 ° C to 50 ° C, particularly preferably 25 ° C to 50 ° C.

  Next, the solid-liquid separation device 4 separates the slurry S discharged from the powder dissolution / reaction vessel 2 into dehydrated cake C (solid phase) made of incinerated ash from which chlorine is eluted and drainage W2 (liquid phase). (STEP06 in FIG. 2) (dehydration step).

  The water content of the dehydrated cake C separated in the dehydration step is preferably 30 to 70% by mass in order to prevent chlorine eluted in the liquid phase from the dehydrated cake C from remaining together with the liquid phase.

  In the preferable aspect of this invention, you may make it collect | recover the waste_water | drain W2 isolate | separated at the spin-drying | dehydration process further. The recovered waste water W2 contains salt eluted from the incineration ash, but since the redox potential (ORP) is in a suitable state, it can be reused as it is in the present invention. Therefore, in the embodiment shown in FIG. 1, the waste water W2 recovered as a liquid phase after the solid-liquid separation through the solid-liquid separation device 4 is converted into a powder dissolution / reaction tank 2 by a liquid feeding device (not shown). To be sent to. As the liquid feeding device, a general liquid feeding pump such as a centrifugal pump, a propeller pump, or a rotary pump may be used.

  Finally, the dewatered cake transport device 5 transports the dewatered cake C to the cement manufacturing facility K, and ends the current process (STEP07 in FIG. 2).

  As described above, in the treatment system 1, when chlorine is eluted from the chlorine-containing powder P that is the slurry S, the relationship between the pH of the slurry S and the oxidation-reduction potential (ORP) is as follows: Adjustment is made so as to satisfy both of the expressions (2). Thereby, chlorine can be selectively eluted and removed.

  Finally, the test results related to the processing performed in the processing system 1 (that is, the embodiment of the processing method of the chlorine-containing powder of the present invention) will be described.

  First, the test method will be described.

  As the chlorine-containing powder P, waste incineration fly ash (chlorine content: 21.2% by mass) was used, and tap water was used as the water W1 to produce slurry S. The mixing ratio was set as waste incineration fly ash: tap water = 1: 4. The pH of the slurry S during production was 12, and the oxidation-reduction potential (ORP) was −20 mV.

  Thereafter, as shown in Table 1, to the produced slurry S, different amounts of ORP adjuster A1 and dilute sulfuric acid as a pH adjuster are added to prepare a plurality of types of samples having different oxidation-reduction potentials (ORP) and pH. And each was stirred at 30 ° C. for 1 hour. As the ORP adjuster, a 25% by mass aqueous solution of sodium hydrogen sulfide was used.

  In addition, in order to confirm the effect of reducing the amount of ORP regulator used due to the reuse of waste water W2, the first test ("Examples") was conducted for Example 13 in which the oxidation-reduction potential (ORP) was -600 mV and the pH was 12. 13-1 "). A test (referred to as" Example 13-2 ") that reused the liquid phase recovered in step 3) and a test that was used again (referred to as" Example 13-3 "). went. The mixing ratio in Example 13 was garbage incineration fly ash: tap water: reused wastewater = 1: 4: 2.

  Thereafter, for the solid phase obtained by solid-liquid separation of the slurry S after stirring with a filter press, the chlorine content was measured by a method in accordance with JIS R 5204 “Method for X-ray fluorescence analysis of cement”. For the liquid phase, the concentration of dissolved heavy metals (Pb, Cd, Cu, Zn) was measured. Here, regarding the desalination rate (%) obtained by dividing the chlorine content (% by mass) of the obtained solid phase by the chlorine content (21.2% by mass) of the above-mentioned refuse incineration fly ash, In all Examples and Comparative Examples shown in Table 1, since it was the same level as 96.5 to 99.0% by mass, it was excluded from the comparative items. In addition, the measurement of the heavy metal density | concentration in a liquid phase used ICP mass spectrometry (usage apparatus: Agilent Technologies Agilent 7900 ICP-MS (brand name)).

  Table 1 shows the test results of the heavy metal concentration in the liquid phase. Further, based on the results, FIG. 3 shows a relationship diagram between pH and oxidation-reduction potential (ORP) representing the application range of the present invention.

From Table 1 and FIG. 3, when the relationship between the pH of the slurry S and the oxidation-reduction potential (ORP) satisfies both the following formula (1) and the following formula (2), chlorine is selectively eluted from the chlorine-containing powder. You can see that
(ORP (mV)) ≦ −150 × (pH) +1400 (1)
(ORP (mV)) ≦ 40 × (pH) −320 (2)
(However, in both formulas (1) and (2), the pH range is 3 ≦ pH ≦ 12.)

  Furthermore, from Examples 13-1 to 13-3 in Table 1, even if the amount of ORP regulator used is reduced by repeated use of wastewater W2 by solid-liquid separation, the effect of suppressing elution of heavy metals may not be affected. Recognize.

DESCRIPTION OF SYMBOLS 1 ... Chlorine-containing powder processing system, 2 ... Powder dissolution / reaction tank, 3 ... Drug addition device, 4 ... Solid-liquid separation device, 4a ... Water washing device, 5 ... Dehydrated cake transport device, 6 ... Control device, DESCRIPTION OF SYMBOLS 21 ... Stirrer blade, 22 ... Thermometer, 23 ... ORP meter (ORP measuring device), 24 ... Heating device, A1 ... ORP regulator, C ... Dehydrated cake, G1 ... Hot gas, K ... Cement production equipment, P ... Chlorine Containing powder, S ... slurry, W1 ... water, W2 ... waste water.

Claims (9)

A slurrying step in which at least water is added to the chlorine-containing powder to form a slurry; and
ORP adjustment step of adjusting the oxidation-reduction potential of the slurry so that the relationship between the pH of the slurry and the oxidation-reduction potential (ORP) satisfies both the following formula (1) and the following formula (2):
An elution step for eluting chlorine contained in the chlorine-containing powder in the slurry in which the oxidation-reduction potential has been adjusted;
And a dehydrating step of dehydrating the slurry from which the chlorine has been eluted to obtain a cement raw material.
(ORP (mV)) ≦ −150 × (pH) +1400 (1)
(ORP (mV)) ≦ 40 × (pH) −320 (2)
(However, in both formulas (1) and (2), the pH range is 3 ≦ pH ≦ 12.) In the processing method of the chlorine containing powder of Claim 1,
In the ORP adjustment step, the relationship between the pH of the slurry and the oxidation-reduction potential (ORP) is satisfied in addition to both the formula (1) and the formula (2), and further satisfies the following formula (3): A method for treating chlorine-containing powder, which is the ORP adjustment step of adjusting the oxidation-reduction potential of the slurry.
(ORP (mV)) ≧ −600 (3) In the processing method of the chlorine containing powder of Claim 1 or Claim 2,
Comprising an ORP measurement step of measuring the oxidation-reduction potential of the slurry obtained in the slurrying step,
When the relationship between the pH of the slurry and the oxidation-reduction potential does not satisfy either the formula (1) or the formula (2), an ORP regulator is added to the slurry in the ORP adjustment step. A method for treating a chlorine-containing powder, wherein the oxidation-reduction potential is adjusted so as to satisfy both the formula (1) and the formula (2). In the processing method of the chlorine containing powder of Claim 3,
The method for treating chlorine-containing powder, wherein the ORP regulator is sodium hydrogen sulfide. In the processing method of the chlorine containing powder of any one of Claims 1-4,
A method for treating chlorine-containing powder, characterized in that wastewater recovered in the dehydration step is reused in the slurrying step, the ORP adjustment step, and the elution step. In the processing method of the chlorine containing powder of any one of Claims 1-5,
In the elution step, the temperature of the slurry is set to 5 to 50 ° C. A powder dissolution and reaction tank for slurrying the contained chlorine-containing powder;
The oxidation / reduction of the slurry so that the relationship between the pH of the slurry contained in the powder dissolution / reaction vessel and the oxidation-reduction potential (ORP) satisfies both the following formulas (1) and (2). An ORP adjustment device for adjusting the potential;
A chlorine-containing powder processing system comprising a solid-liquid separation device for solid-liquid separation of the slurry discharged from the powder dissolution / reaction tank.
(ORP (mV)) ≦ −150 × (pH) +1400 (1)
(ORP (mV)) ≦ 40 × (pH) −320 (2)
(However, in both formulas (1) and (2), the pH range is 3 ≦ pH ≦ 12.) The chlorine-containing powder processing system according to claim 7,
In the ORP adjusting device, the relationship between the pH of the slurry accommodated in the powder dissolution / reaction vessel and the oxidation-reduction potential (ORP) is added to both the formula (1) and the formula (2). The chlorine-containing powder processing system is the ORP adjusting device for adjusting the oxidation-reduction potential of the slurry so that the following formula (3) is also satisfied.
(ORP (mV)) ≧ −600 (3) The chlorine-containing powder processing system according to claim 7 or 8,
An ORP measuring device for measuring the redox potential of the slurry produced in the powder dissolution / reaction vessel;
A chlorine-containing powder processing system comprising: a control device that automatically controls the ORP adjustment device based on a measurement result of the ORP measurement device.