CN107098556B - Method for recycling metal from sludge in steel wire rope production - Google Patents

Abstract

The invention discloses a method for recycling metals from sludge in steel wire rope production, belonging to the project of environmental protection and resource recycling. The sludge and waste acid in the steel wire rope factory contain quite high heavy metal lead (more than 2000 ppm), the economic requirement of industrial extraction is not met under the normal state, and the steel wire rope enterprise cannot process the heavy metal lead. The sludge and the waste acid are mixed and reacted, and then the problem of difficult treatment of the sludge and the waste acid is well solved by an electrochemical method.

Description

Method for recycling metal from sludge in steel wire rope production

Technical Field

The invention relates to a method for recycling metals from sludge in steel wire rope production, belonging to the technical field of environmental engineering.

Background

Sludge and waste acid from steel wire rope enterprises contain heavy metals (iron, zinc, lead and the like), oxides and salts, the components are quite complex, and the sludge and the waste acid are treated by a resin adsorption method, but the sludge and the waste acid cannot be accepted by the enterprises due to high cost. The mixed slag obtained by adopting an alkali neutralization method causes secondary pollution, and the search for an economical and feasible method for treating sludge and waste acid is an effort for many years.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for recycling metals from sludge in steel wire rope production.

The invention is realized by the following technical scheme:

the invention provides a method for recycling metals from sludge in steel wire rope production, which comprises the following steps:

reacting sludge in the production of the steel wire rope with waste acid, and performing solid-liquid separation to obtain solid waste containing acid hydrochloride and phosphate;

electrolyzing by taking the acid-containing hydrochloride as electrolyte, iron as an anode and aluminum as a cathode to deposit heavy metal ions in the electrolyte on the cathode;

respectively collecting the heavy metal simple substance on the cathode and the electrolyzed electrolyte;

and adding sodium sulfide into the electrolyzed electrolyte, adjusting the pH value to be not more than 2, and carrying out solid-liquid separation after reaction to obtain ferrous chloride and zinc sulfide.

Preferably, the pH value of the acid-containing hydrochloride is 1.5-2.

According to a preferable scheme, the weight ratio of the sludge to the waste acid is 1 (2-8).

Preferably, the current density and voltage of the electrolysis are 2000A/m2 and 0.6-1.6V respectively.

The basic principle of the invention is as follows:

1. the method comprises the steps of mixing sludge and waste acid according to a certain proportion for reaction (because the components of the sludge and the waste acid are relatively unstable, sampling and testing of each batch are necessary), and performing primary solid-liquid separation after the reaction to obtain a solid serving as an iron phosphate raw material.

2. The pH value of the separated liquid is 1.5-2 (a small amount of acid value is reserved), and the mixed solution mainly contains chloride (copper, lead, zinc, iron and the like).

3. Feeding the solution into an electrolytic bath, wherein the electrolytic current is 2000A/m2, the voltage is 0.6-1.6V, relatively inactive metal ions in the solution are converted into elemental metal (available on the market) at a cathode through electrolysis, and anode iron enters the solution under the action of the current to be converted into ferrous chloride.

4. The ferrous chloride solution also contains zinc chloride, the zinc chloride solution is changed into zinc sulfide by sodium sulfide treatment, the pH is adjusted to be below 2, the ferrous chloride obtained by solid-liquid separation after reaction can be directly sold on the market, and the zinc sulfide can be further purified and sold on the market.

Compared with the prior art, the invention has the following beneficial effects:

through the treatment in the process, the sludge and the waste acid in the steel wire rope plant are comprehensively utilized, so that the treatment burden of enterprises is reduced, and the waste is changed into resources for utilization.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1

The embodiment relates to a method for recycling metals from sludge in steel wire rope production, which comprises the following steps:

w/%, on a dry basis, for sludge from steel mills, iron: 26%, lead: 0.5%, zinc: 7.5%, copper: 0.01%, phosphorus: 0.1%, waste acid (as HCl) w/%: 7.9%, iron: 13%, lead: 0.25%, zinc: 0.1%, phosphorus: 0.1%, copper: 0.01 percent and the solid-liquid ratio of 1:3.5, and the solid-liquid separation is carried out after the reaction, and the pH value of the solution is 1.9.

Feeding the obtained solution into an electrolytic cell, wherein the anode is an iron plate, the cathode is an aluminum plate, and the current is 2000A/m²The voltage was 0.8V, and after electrolysis, a mixture of metallic lead and copper (a small amount of copper) was obtained at the cathode and was commercially available.

Adding refined sodium sulfide (0.1005mol/L) into the electrolyte, adjusting the pH value to 1.5 by using hydrochloric acid, and carrying out solid-liquid separation after reaction to obtain a water purifying agent ferrous chloride and a crude product zinc sulfide.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims (2)

1. A method for recycling metals from sludge in steel wire rope production is characterized by comprising the following steps:

reacting sludge in the production of the steel wire rope with waste acid, and performing solid-liquid separation to obtain solid waste containing acid hydrochloride and phosphate; the weight ratio of the sludge to the waste acid is 1 (2-8);

electrolyzing by taking the acid-containing hydrochloride as electrolyte, iron as an anode and aluminum as a cathode to deposit heavy metal ions in the electrolyte on the cathode; the current density and voltage of the electrolysis are respectively 2000A/m²And 0.6-1.6V;

respectively collecting the heavy metal simple substance on the cathode and the electrolyzed electrolyte;

and adding sodium sulfide into the electrolyzed electrolyte, adjusting the pH value to be not more than 2, and carrying out solid-liquid separation after reaction to obtain ferrous chloride and zinc sulfide.

2. The method for recycling metals from sludge in steel wire rope production according to claim 1, wherein the pH value of the acid-containing hydrochloride is 1.5-2.