HJ 2057-2018Technical specification for wastewater treatment of lead smelting (English PDF)

3.1 Waste acid waste acid

Refers to heavy metal ions such as suspended solids, lead, arsenic, etc. produced during the acid washing and purification process of lead smelting flue gas.

A dilute sulfuric acid solution of contaminants such as impurities.

3.2 Acidic wastewater containing heavy metals

Waste water containing heavy metal ions, acids, suspended solids and other pollutants produced during the lead smelting process.

3.3 Lead smelting wastewater lead smelting wastewater

Refers to the various contaminated production wastewater generated during the lead smelting production process.

4.1 Wastewater source and classification

4.1.1 Waste acid

The waste acid is mainly produced in the acid purification section. The main pollutants are suspended solids, heavy metal ions, fluoride and other harmful substances.

Impurities.

4.1.2 Acidic wastewater containing heavy metals

Acidic wastewater containing heavy metals is mainly produced in the acid purification section, electric defogging, slag, wet dust collection, wet process, Ground rinsing, laboratory, and slag reservoir percolation, etc., the main pollutants are heavy metal ions, acids, suspended solids and so on.

4.1.3 Initial rain

The initial rainwater is mainly smoke (ash) dust enriched in the surface, roof and equipment of the plant during the lead smelting process.

The initial runoff from the formation of rainwater, the main pollutants are pH, suspended matter, heavy metal ions and so on.

4.1.4 General production wastewater

General production wastewater is mainly produced in boilers, chemical water treatment stations, public and auxiliary supporting production processes, and indirect circulating cooling.

But the system. The main pollutants are salt, suspended solids, oil, alkali and acid.

The sources and classification of lead smelting wastewater are shown in Table 1.

Table 1 Source and classification of lead smelting wastewater

Wastewater species source major pollutants

1 Waste water from waste acid acid flue gas washing Suspended matter, heavy metal ions, Fluoride and other harmful impurities

2 Waste water suspended, heavy metal ions, generated by electric defogging and washing in heavy metal acid purification section Acid wastewater, defogging, washing acid, etc.

Slag

Melting in fire smelting Melting slag for water quenching Waste water Suspended matter, heavy metal ions, etc.

Wet dust collection

Wet dust collection and defogging open circuit Waste water Suspended matter, heavy metal ions, etc.

Wet workshop

During the wet smelting process Raw wastewater Suspended matter, heavy metal ions, Salt, etc.

Ground flush

For equipment, flooring, filter materials, etc.

Waste water produced by flushing, package Including electrolysis or other wet processes Owing to leakage during operation Waste liquid Suspended matter, heavy metal ions, Acid Heavy metal ions in wastewater produced by laboratory analysis and assay Harmful slag reservoir percolation Waste residue storage, yard, landfill Leachate Suspended matter, heavy metal ions, Acid

3 Initial rainwater in the contaminated area of the initial rainwater smelting plant area Suspended matter, heavy metal ions, Acid General production Waste water Boiler, chemical water treatment Chemical water treatment station discharge Raw wastewater Salt, alkali, acid, etc.

Production of public auxiliary equipment Process Machine repair workshop, air compressor station, blast Waste water from the engine room Suspended matter, oil, etc.

Indirect circulation cooling system Cooling smelting furnace, fan, pump Waste water from equipment

4.2 Wastewater volume

4.2.1 The amount of wastewater generated by existing enterprises is determined through actual measurement. The amount of wastewater generated by newly-built enterprises can be based on product variety, production process, the analogy of production scale, work system and management level can also be determined according to material balance and water balance.

4.2.2 The amount of lead smelting wastewater can also be referred to the following data. the amount of lead acid produced per ton of lead is 0.1~0.6t, and the lead per ton contains heavy gold.

The amount of acid wastewater generated is 8~17t.

4.2.3 The initial rainwater collection should be carried out in accordance with GB 50988.

4.3 Wastewater quality

4.3.1 Waste acid, heavy metal acid wastewater and initial rainwater pollutants and concentrations determined by actual measurement, new enterprises Companies that can be compared to raw materials, production processes, equipment levels, and management levels can also be based on material balance and water balance.

determine.

4.3.2 When there is no actual or analog data, the main pollutant components and concentration range of waste acid and heavy metal acid wastewater can be referred to

Table 2, Table 3.

Table 2 Main pollutant components and concentration of waste acid (unit. mg/L, sulfuric acid unit. %)

Total lead total cadmium total arsenic total mercury fluoride sulfuric acid Content 20~500 20~300 100~3200 1~10 100~1000 1~10

Table 3 Main pollutants and concentrations of heavy metal acid wastewater (unit. mg/L, except pH)

Ingredients total cadmium total arsenic total lead total zinc total mercury fluoride sulfuric acid pH SS Content 5~50 10~50 5~50 10~100 0.01~1 10~50 500~1500 <=6 100~2000

5.1 General provisions

5.1.1 Construction and operation management of lead smelting enterprises shall comply with relevant national and local laws and regulations, industrial policies, planning and other management.

Requirements, and actively promote clean production, improve resource and energy utilization.

5.1.2 Construction of lead smelting enterprises involves the production of heavy metals and other toxic and hazardous substances, storage tanks and pipelines, or construction of sewage Facilities with treatment risks such as treatment pools and emergency pools shall be designed in accordance with the requirements of relevant national standards and regulations.

Construction and installation of anti-corrosion, leak-proof facilities and leak monitoring devices to prevent contamination of soil and groundwater.

5.1.3 The lead smelting wastewater treatment project shall comply with the requirements of the environmental impact assessment document, and be designed and applied simultaneously with the main project.

Work and use at the same time.

5.1.4 The construction scale and process configuration of the lead smelting wastewater treatment project should be coordinated with the production system of the enterprise, and the park where the enterprise is located the planning of the district and the local drainage plan are in line with each other, and the construction project of the phased construction should meet the requirements of the overall planning of the enterprise.

5.1.5 Lead smelting wastewater discharge should meet the requirements of GB 25466 and local discharge standards, and meet the environmental impact assessment approval documents.

The provisions, and meet the requirements of total pollutant control and discharge permit management, should be satisfied with the production water after treatment and reuse Water quality requirements.

5.1.6 Lead smelting wastewater treatment project should adopt secondary pollution prevention measures to prevent waste gas and waste generated in wastewater treatment process Water and waste slag pollute the environment.

5.1.7 Lead smelting wastewater treatment projects shall adopt measures such as noise prevention and earthquake resistance during construction and operation. Treatment facility, construction (construction) Buildings and the like shall take anti-corrosion according to the nature of the contact medium, especially the facilities and structures (structures) that are exposed to waste acid and wastewater.

Anti-leakage, anti-seepage and other measures, anti-seepage should meet the requirements of GB 50988.

5.1.8 Lead smelting wastewater treatment project shall be equipped with accident emergency prevention facilities, and shall be set at the site that may be contaminated by heavy metals.

Rainwater collection pool.

5.1.9 The standardized sewage outfall should be set according to the Technical Requirements for Standardization and Remediation of Sewage Discharges (Trial) (Environmental Supervision [1996] No. 470).

Install metering and automatic monitoring systems and meet HJ/T 353, HJ/T 354, HJ/T 355 and HJ/T 212 requirements.

5.2 Source Control

5.2.1 Lead smelting enterprises should promote clean production, improve water recycling rate and price through source control and process management.

The recovery rate of metal reduces the amount of wastewater generated.

5.2.2 The wastewater generated by the lead smelting enterprises shall be collected and classified, and the sewage shall be diverted and diverted.

5.2.3 Waste acid and heavy metal acid wastewater should be reused after treatment.

5.2.4 The slag is treated with treated wastewater and recycled.

5.3 Project scale

5.3.1 The scale of wastewater treatment should be 1.2~1.5 times of the amount of wastewater generated, and should meet the requirements of production fluctuations to meet the overall enterprise.

Planning requirements.

5.3.2 The volume of waste acid and heavy metal acid wastewater adjustment tank should be calculated and determined according to the change rule of wastewater volume, and the effective volume should be accepted.

Set the amount of wastewater not less than 8h.

5.3.3 The effective volume of the accident pool should consider the amount of material leakage, fire water and rainfall.

5.3.4 The initial rainwater collection tank volume shall be implemented in accordance with GB 50988.

5.4 Engineering composition

5.4.1 Wastewater treatment projects include the treatment of buildings (structures) and equipment, auxiliary works and supporting facilities.

5.4.2 Wastewater treatment and construction (construction) and equipment include. wastewater collection, regulation, treatment, reuse and discharge, sludge concentration and dehydration, pharmaceutical preparation and dosing, electrical and automatic detection and control.

5.4.3 Auxiliary works include. plant roads, fences, green space projects; independent power supply projects and water supply and drainage projects, for compression Air, ventilation and dust removal system; dedicated laboratories, control rooms, warehouses, maintenance workshops, temporary sludge storage sites, etc.

5.4.4 Supporting facilities include. office, lounge, bathroom and other living facilities.

5.5 Project site selection and overall layout

5.5.1 The site selection of wastewater treatment works shall comply with the provisions of GB 50014, GB 50187 and GB J 22.

5.5.2 The layout of the wastewater treatment project should meet the functions and processing requirements of each treatment unit, and build (structure) and design the spacing of the application should be compact and reasonable, and meet the requirements of construction and installation; the process equipment should be classified according to the treatment process and the nature of wastewater.

Arranged, the equipment is arranged neatly and reasonably, easy to operate and maintain.

5.5.3 The wastewater treatment project shall be provided with a collection system for ground flushing water and equipment leakage water, and discharged into the wastewater regulating tank.

5.5.4 The selection and installation of pipelines for wastewater treatment projects shall comply with the corresponding pipeline installation and operation specifications. Cold area, its room External piping and equipment should be insulated.

5.5.5 Transportation of waste acid, heavy metal acid wastewater and acid and alkali pipelines should be simple and easy to avoid mutual interference;

It is convenient for maintenance management.

5.5.6 Wastewater treatment works should be close to the production process of waste acid and heavy metal acid wastewater, reducing the potential of long-distance transport.

Circumstances and security risks.

6.1 General requirements

6.1.1 Before the process design, comprehensively investigate the water quality, quantity and variation of wastewater, and conduct necessary analysis and measurement.

test.

6.1.2 The choice of wastewater treatment process should give priority to the recovery of valuable metals or comprehensive treatment processes.

6.1.3 After the wastewater treatment, the external drainage should meet the requirements of GB 25466 and corresponding local discharge standards, and meet the environmental impact assessment.

The price approval document requirements. The area where the total amount of key pollutants is controlled shall meet the requirements of total control.

6.1.4 Waste acid, heavy metal acid wastewater, and initial rainwater should not be mixed with general production wastewater.

6.2 Process selection

6.2.1 The choice of wastewater treatment process should be based on the water quality characteristics of the wastewater, the destination of the treated water and the requirements of the discharge standard.

After the technical and economic comparison, it is determined.

6.2.2 Waste acid should be considered according to the pre-treatment process of wastewater treatment. The process should adopt lime neutralization method, lime iron salt method and vulcanization method lime.

Neutralization method, etc. The waste acid treatment process and the return of the liquid are shown in Figure 1.

Waste acid

Lime neutralization

Lime iron salt method Sulfurized lime neutralization method Heavy metal acid Wastewater treatment station Reuse

Figure 1 Schematic diagram of waste acid treatment route

6.2.3 Treatment process of heavy metal acidic wastewater should adopt lime neutralization method, high concentration mud method, lime iron salt method and electrochemistry Method, membrane separation method, adsorption method, filtration method, and the like. The treatment process of heavy metal-containing acidic wastewater and the treatment of treated wastewater are shown in Figure 2.

Heavy metal

Acid wastewater

Lime neutralization

High concentration mud method Lime iron salt method Electrochemical method Reuse Membrane separation Adsorption method Discharge Reuse or reach Standard discharge Filtration

Figure 2 Schematic diagram of treatment route for heavy metal acid wastewater

6.2.4 When the concentration of arsenic is greater than 50mg/L, it should be treated by lime iron salt method.

6.2.5 Electrochemical treatment processes generally require pretreatment and can be used in conjunction with lime neutralization.

6.2.6 Strict control of heavy metal efflux areas can be continued by membrane separation, filtration, adsorption and other processes.

6.2.7 The initial rainwater can be reused after being treated with heavy metal collectors, or mixed with heavy metal acid wastewater.

6.2.8 The hot polluted water discharged from the boiler in general production wastewater should be reused after treatment; the acid and alkali waste discharged from the chemical water station the water should be reused after being treated separately; the production drainage generated in the public auxiliary system should be collected and reused; indirect circulating cooling the sewage should be reused after being collected and treated.

6.3 Main process unit

6.3.1 Lime neutralization method

6.3.1.1 The basic process of lime neutralization is shown in Figure 3.

Solid-liquid separation of wastewater Sludge dewatering Further or reuse Homogenization and neutralization reaction Neutralization residue Flocculant filtrate Neutralizer

Figure 3 Basic process flow chart of lime neutralization method

6.3.1.2 The following technical conditions and requirements shall be met when the lime neutralization process is carried out.

(1) Commonly used neutralizing agents mainly include limestone, lime milk, liquid alkali and calcium carbide slag;

(2) The neutralization reaction time should be controlled above 30 min;

(3) The sedimentation tank should be mechanically scraped, and the slope of the bucket should not be less than 5%;

6.3.2 Vulcanization method

6.3.2.1 The basic process flow of the vulcanization process is shown in Figure 4.

Equalization adjustment of wastewater pH adjustment Vulcanizing agent Sulfurization reaction solid-liquid separation filtrate Further or reuse

Figure 4 Basic process flow chart of vulcanization method

6.3.2.2 The following technical conditions and requirements shall be met for the treatment of vulcanization.

(1) The dosage of the vulcanizing agent should be automatically controlled by oxidation reduction potential (ORP);

(2) The vulcanization process should be carried out in a closed container, and the hydrogen sulfide gas escaping during the process should be absorbed.

And meet the discharge requirements;

(3) The time of vulcanization reaction should be determined according to the test, and should not be less than 60 min;

(4) When the arsenic co...