Method for treating heavy metal in solid waste incineration fly ash through magnetite modification

[0039] Example 1

[0040] A kind of embodiment of the method that the present invention utilizes magnetite modifier to process heavy metals in solid waste incineration fly ash, the method comprises the following steps:

[0041] (1) Leaching of heavy metals in fly ash containing copper, zinc, cadmium and lead: mix hydrochloric acid with a pH value of 2 and fly ash at a weight ratio of 14:1, and stir for 20 hours to obtain a leachate, and measure copper, The leaching rate of cadmium is close to 100%, and the leaching rate of zinc and lead is 80-85%;

[0042] (2) Extract metal zinc and copper: get 10 parts by volume of the leaching solution obtained in step (1) to adjust the pH value to 4, and then use 10 parts by volume of 5-nonylsalicylaldoxime concentration of 1mol/L of 5 -The mixed solution of nonylsalicylaldoxime and kerosene extracts it, obtains aqueous phase A and the organic phase of loading copper, then uses 10 parts by volume of dithiophosphonic acid 572 concentration to be the dithiophosphonic acid 572 of 1mol/L and The mixed solution of kerosene extracts the aqueous phase A to obtain the residual liquid (residual aqueous phase) and the organic phase loaded with zinc, wherein each extractant is extracted once, and the time of each extraction is 5 minutes; The organic phase and the sulfuric acid solution with a concentration of 1.5-5mol/L were mixed at a volume ratio of 10:10 and stripped for 5 minutes to recover copper. The organic phase loaded with zinc and the nitric acid solution with a concentration of 0.1-6mol/L were Volume ratio 10:10 mixed and carried out stripping treatment 5 minutes to reclaim zinc, wherein the extraction rate of copper is 100%, and the stripping rate is 95%, can reclaim 95% of copper in the leachate; The extraction rate of zinc is 90%. %, the stripping rate is 91%, and 82% of the zinc in the leachate can be recovered;

[0043] (3) Adsorption of heavy metal cadmium and lead: Add humic acid-modified magnetite to the residual liquid obtained in step (2) at a liquid-solid ratio of 100mL:1g, oscillate and adsorb at room temperature until equilibrium is reached, and the humic acid modified magnetite is measured. The removal rate of acid-modified magnetite to cadmium is more than 99%, and the removal rate to lead is more than 95%, and all adsorptions reach equilibrium within 3 hours.

[0044] Example 2

[0045] A kind of embodiment of the method that the present invention utilizes magnetite or its modifiers to process heavy metals in solid waste incineration fly ash, the method comprises the following steps:

[0046] (1) Leaching of heavy metals in fly ash containing copper, zinc, cadmium and lead: mix hydrochloric acid with a pH value of 2 and fly ash at a weight ratio of 10:1, and stir for 18 hours to obtain a leachate, and measure copper, The leaching rate of cadmium is close to 100%, and the leaching rate of zinc and lead is 78-82%;

[0047] (2) Extract metal zinc and copper: get 10 parts by volume of the leaching solution obtained in step (1) to adjust the pH value to 4, and then use 8 parts by volume of 5-nonylsalicylaldoxime concentration of 1mol/L of 5 -The mixed solution of nonylsalicylaldoxime and kerosene extracts it, obtains aqueous phase A and the organic phase of loading copper, then uses 8 parts by volume of dithiophosphonic acid 572 concentration to be the dithiophosphonic acid 572 of 1mol/L and The mixed solution of kerosene extracts the aqueous phase A to obtain the residual liquid (residual aqueous phase) and the organic phase loaded with zinc, wherein each extractant is extracted once, and the time of each extraction is 5 minutes; The organic phase and the sulfuric acid solution with a concentration of 1.5-5mol/L were mixed at a volume ratio of 10:8 and stripped for 5 minutes to recover copper. The organic phase loaded with zinc and the nitric acid solution with a concentration of 0.1-6mol/L were Volume ratio 10:8 mixed and carried out stripping treatment 5 minutes to reclaim zinc, wherein the extraction rate of copper is 100%, and the stripping rate is 88-94%, can reclaim the copper of 88-94% in the described leaching liquid; The extraction rate is 87%, the stripping rate is 90-92%, and 78-80% of the zinc in the leachate can be recovered;

[0048] (3) Adsorption of heavy metal cadmium and lead: Humic acid modified magnetite is added to the residual liquid obtained in step (2) with a liquid-solid ratio of 100mL:0.5g, and the adsorption is oscillating at room temperature until equilibrium is reached, and the humic acid modified magnetite is measured. The removal rate of cadmium modified by phytic acid modified magnetite is more than 99%, and the removal rate of lead is more than 95%, and all adsorptions reach equilibrium within 3 hours.

[0049] Example 3

[0050] A kind of embodiment of the method that the present invention utilizes magnetite or its modifiers to process heavy metals in solid waste incineration fly ash, the method comprises the following steps:

[0051] (1) Leaching of heavy metals in fly ash containing copper, zinc, cadmium and lead: mix hydrochloric acid with a pH value of 2 and fly ash at a weight ratio of 15:1, and stir for 24 hours to obtain a leachate, and measure copper, The leaching rate of cadmium is close to 100%, and the leaching rate of zinc and lead is 82-85%;

[0052] (2) Extract metal zinc and copper: get 10 parts by volume of the leaching solution obtained in step (1) to adjust the pH value to 4, and then use 15 parts by volume of 5-nonylsalicylaldoxime concentration of 1mol/L of 5 -The mixed solution of nonylsalicylaldoxime and kerosene extracts it, obtains aqueous phase A and the organic phase of loading copper, then uses 15 parts by volume of dithiophosphonic acid 572 concentration to be the dithiophosphonic acid 572 of 1mol/L and The mixed solution of kerosene extracts the aqueous phase A to obtain the residual liquid (residual aqueous phase) and the organic phase loaded with zinc, wherein each extractant is extracted once, and the time of each extraction is 5 minutes; The organic phase and the sulfuric acid solution with a concentration of 1.5-5mol/L were mixed at a volume ratio of 10:15 and stripped for 5 minutes to recover copper. The organic phase loaded with zinc and the nitric acid solution with a concentration of 0.1-6mol/L were Volume ratio 10:15 was mixed and stripped for 5 minutes to reclaim zinc, wherein the extraction rate of copper was 100%, and the stripping rate was 94-98%, and 94-98% of copper in the leaching solution could be recovered; zinc The extraction rate is 94%, the stripping rate is 92-97%, and 86-91% of the zinc in the leachate can be recovered;

[0053] (3) Adsorption of heavy metal cadmium and lead: Add humic acid-modified magnetite to the residual liquid obtained in step (2) with a liquid-solid ratio of 100mL:2g, oscillate and adsorb at room temperature until equilibrium is reached, and the humic acid modified magnetite is measured. The removal rate of acid-modified magnetite to cadmium is more than 99%, and the removal rate to lead is more than 95%, and all adsorptions reach equilibrium within 3 hours.