CN104532002A - Lead-containing glass resourceful treatment method - Google Patents

Abstract

The invention relates to a lead-containing glass resourceful treatment method, and belongs to the field of waste resourceful treatment. The lead-containing glass resourceful treatment method comprises following four steps: smashing of lead-containing glass; reduction roasting with alkali, water washing for lead recovery, and recovery of silicon dioxide; silicon dioxide is changed into water soluble silicate via reduction roasting with alkali; oxides of lead are changed into lead via reduction with powdered carbon; and then recovery of lead and silicon dioxide is realized via water washing and separation. The lead-containing glass resourceful treatment method is short in route, low in cost, and high in lead and silicon dioxide recovery rate; and is capable of realizing complete recovery of lead and silicon dioxide.

Description

Recycling method of lead-containing glass

technical field

The invention relates to a resource treatment method for lead-containing glass, and belongs to the field of waste resource treatment.

technical background

Leaded glass refers to glass containing glass formers such as silica and a relatively high content of lead oxide. Because of its good optical performance, electrical conductivity, radiation protection performance and processability, etc., it is widely used in the manufacture of electric vacuum glass, low temperature sealing glass, radiation protection glass, optical glass, high refraction bead glass and art utensil glass and other products. Cathode ray tube (CRT), as an important leaded glass product, is widely used in electronic and electrical equipment such as televisions, computer monitors, and oscilloscopes. The CRT glass bulb is an important part of the display, accounting for about 50% of the total weight. CRT glass bulbs are mainly divided into screen glass and cone glass, of which the lead content of cone glass is about 22-28%. At present, there are about 550 million TV sets in my country, the vast majority of which are CRT TV sets, and the number of computer CRT monitors has exceeded 40 million sets, and a large number of electronic and electrical products have entered the peak period of elimination and scrapping. If a large amount of lead-containing glass is not properly disposed of, it will not only cause a waste of lead resources, but also pose a potential threat to human health and the ecological environment.

At present, countries all over the world do not have good treatment and disposal methods for high lead-containing glass. It is feasible to use waste lead-containing glass to develop resource-based products. The main problem is that the resource utilization rate is low, and the lead in glass is only transferred from one product to another, and the problem of heavy metal hazards has not been completely resolved. At present, the raw material for lead production in my country is mainly high-grade galena. Due to resource constraints, a large amount of lead concentrate raw materials need to be imported every year, and lead smelting generally adopts the traditional sintering-blast furnace smelting process, which will produce a large amount of sulfur dioxide and Lead dust is a serious environmental pollution. Therefore, extracting lead from waste lead-containing glass may become a research hotspot and development trend in the future. However, there are some technical bottlenecks and environmental problems in the current lead extraction methods, and it is difficult to achieve industrialization. It is urgent to develop an efficient, low-energy, and clean lead extraction process.

In 2008, Wu Guoqing and others reported "Research on Recycling Technology of Displays Containing CRT" from the perspectives of material classification and identification, material harmless treatment, material separation and reuse. In the same year, Yin Fengfu of Haier Group Technology R&D Center and others reported "Environmental Protection Treatment Technology of Waste Displays", and its partner Qingdao Xintiandi developed a CRT comprehensive utilization process and built a corresponding disposal and recycling plant, but its technical core is limited to CRT. The dismantling and sorting of CRT does not involve the industrial production method of extracting lead from CRT for reuse.

The Chinese patent with the publication number CN101613802A provides a process and supporting equipment for recycling lead from waste leaded glass and simultaneously producing environmentally friendly building materials. It can use waste leaded glass as raw material to recover lead in vacuum carbon thermal reduction process and prepare foam glass . However, due to the short steps of this process, only lead and the corresponding chemical product foam glass can be recovered at the same time, and this method needs to be reacted at 1000 ° C for several hours, so the required equipment is high, energy consumption is large, and pollution is large, so it is not conducive to industrialization. Production.

Contents of the invention

In view of the above existing problems, the object of the present invention is to provide a method for recycling lead-containing glass. This method has a short process flow, low cost, can fully utilize lead and silicon dioxide, and has a high recovery rate of lead and silicon dioxide.

The technical scheme that the present invention adopts is as follows: the resource processing method of lead-containing glass, it is characterized in that, comprises the following several steps:

1) Breakage of leaded glass. Put the leaded glass into the ball mill and crush it to a particle size of 0.1-1.5mm;

2) Alkali reduction roasting. Mix the crushed lead-containing glass powder with carbon powder and alkali, then granulate it with water, put it into a high-temperature furnace for roasting, the roasting temperature is 300-600°C, and the roasting time is 2-6 hours;

3) Wash and recover lead. Add the roasted material to pure water for slurry, the mass ratio of the roasted material to pure water is 1:5-10, the washing time is 1-5 hours, the washing temperature is 70-100°C, and the 100-300 mesh filter cloth is used after washing Filtration, the filter residue is crude lead;

4) Recovery of silica. Add acid to the water-washed filtrate to adjust the pH to 0.5-4.5, react at 70-99°C for 1-5 hours, then filter, wash the filter residue and roast for 1-5 hours at a roasting temperature of 500-1000°C to obtain di silicon oxide.

In the step 2, the mass ratio of lead-containing glass powder, carbon powder, and alkali is 1:0.5-1.5:0.5-1.0, and the alkali is at least one of sodium hydroxide, barium hydroxide, and potassium hydroxide.

In the step 4, the acid is at least one of sulfuric acid, hydrochloric acid, nitric acid and acetic acid, and the concentration of the acid is 5-10mol/l.

The crude lead is obtained through smelting-electrolytic refining to obtain a lead plate.

The washing is performed until the conductivity of the washing water is less than 200 us/cm.

The principle of the present invention is that lead-containing glass refers to glass containing glass-formers such as silicon dioxide and glass with relatively high content of lead oxide. The lead content is 15-30%, mainly lead oxide and lead dioxide, and the remaining substances are mainly di Silicon oxide, after crushing the lead-containing glass, adding alkali and carbon powder to roast, the alkali and silicon dioxide form silicate, which destroys the glass structure, thereby dissociating the lead oxide wrapped in the glass network structure, while the carbon The powder can reduce the lead oxide to crude lead at high temperature, and then the roasted product is washed with water, the silicate is dissolved in water, and the filter residue is filtered to become crude lead. The crude lead is smelted-electrolytic refining to obtain high-purity lead plate , and sodium silicate is added with acid to adjust the pH to acidity to obtain silicic acid precipitation, and silicic acid is roasted and dehydrated to obtain silica.

The invention has the beneficial effects of short process, low cost, full utilization of lead and silicon dioxide, and high recovery rate of lead and silicon dioxide.

Detailed ways

Example 1

1) Breakage of leaded glass. Put the leaded glass into a ball mill and crush it to a particle size of 1.2mm;

2) Alkali reduction roasting. Mix the crushed lead-containing glass powder with carbon powder and sodium hydroxide, and then granulate with water. The mass ratio of lead-containing glass powder, carbon powder and sodium hydroxide is 1:1.2:0.8, and put it into a high-temperature furnace Roasting, the firing temperature is 550°C, and the firing time is 4 hours;

3) Wash and recover lead. The roasted material is added into pure water to slurry, the mass ratio of the roasted material to pure water is 1:8, the washing time is 3 hours, the washing temperature is 95°C, and after washing, it is filtered with a 250-mesh filter cloth, and the filter residue is crude lead;

4) Recovery of silica. Add sulfuric acid to the washed filtrate to adjust the pH to 3.5, and the concentration of sulfuric acid is 7.5mol/l. React at 95°C for 4 hours, then filter, wash and roast the filter residue until the conductivity of the washing water is 180us/cm, roast for 3 hours, and roast at a temperature of 850°C to obtain silicon dioxide.

The crude lead is obtained through smelting-electrolytic refining to obtain a lead plate.

The final recoveries of lead and silica were 99.6%, 97.1%, respectively.

Example 2

1) Breakage of leaded glass. Put the leaded glass into the ball mill and crush it to a particle size of 0.7mm;

2) Alkali reduction roasting. Mix the crushed lead-containing glass powder with carbon powder and potassium hydroxide, and then granulate with water. The mass ratio of lead-containing glass powder, carbon powder and potassium hydroxide is 1:0.95:0.9, and put it into a high-temperature furnace Roasting, the firing temperature is 550°C, and the firing time is 3.5 hours;

3) Wash and recover lead. The roasted material is added into pure water for slurrying, the mass ratio of the roasted material to pure water is 1:8, the washing time is 4 hours, the washing temperature is 100°C, and after washing, it is filtered with a 200-mesh filter cloth, and the filter residue is crude lead;

4) Recovery of silica. Add hydrochloric acid to the washed filtrate to adjust the pH to 2.5, and the concentration of hydrochloric acid is 8.5mol/l. React at 97°C for 5 hours, then filter, wash and roast the filter residue until the conductivity of the washing water is 150us/cm, roast for 3 hours, and roast at a temperature of 850°C to obtain silicon dioxide.

The crude lead is obtained through smelting-electrolytic refining to obtain a lead plate.

The final recoveries of lead and silica were 99.3%, 97.8%, respectively.

Example 3

1) Breakage of leaded glass. Put the leaded glass into the ball mill and crush it to a particle size of 0.7mm;

2) Alkali reduction roasting. Mix the crushed lead-containing glass powder with carbon powder and potassium hydroxide, and then granulate with water. The mass ratio of lead-containing glass powder, carbon powder and potassium hydroxide is 1:0.95:0.85, and put it into a high-temperature furnace Roasting, the firing temperature is 550°C, and the firing time is 2.5 hours;

3) Wash and recover lead. The roasted material is added into pure water to make a slurry, the mass ratio of the roasted material to pure water is 1:6, the washing time is 4 hours, and the washing temperature is 90°C. After washing, filter with a 250-mesh filter cloth, and the filter residue is crude lead;

4) Recovery of silica. Add hydrochloric acid to the washed filtrate to adjust the pH to 2.5, and the concentration of hydrochloric acid is 8.5mol/l. React at 90°C for 4 hours, then filter, wash and roast the filter residue until the conductivity of the washing water is 150us/cm, roast for 3 hours, and roast at a temperature of 850°C to obtain silicon dioxide.

The crude lead is obtained through smelting-electrolytic refining to obtain a lead plate.

The final recoveries of lead and silica were 99.5%, 98.1%, respectively.

Example 4

1) Breakage of leaded glass. Put the leaded glass into the ball mill and crush it to a particle size of 0.5mm;

2) Alkali reduction roasting. Mix the crushed lead-containing glass powder with carbon powder and sodium hydroxide, and then granulate with water. The mass ratio of lead-containing glass powder, carbon powder and potassium hydroxide is 1:0.78:0.9, and put it into a high-temperature furnace Roasting, the calcination temperature is 450°C, and the calcination time is 3.5 hours;

3) Wash and recover lead. The roasted material is added into pure water for slurrying, the mass ratio of the roasted material to pure water is 1:8, the washing time is 4 hours, and the washing temperature is 85°C. After washing, filter with a 200-mesh filter cloth, and the filter residue is crude lead;

4) Recovery of silica. Nitric acid is added to the water-washed filtrate to adjust the pH to 2.5, and the concentration of nitric acid is 8.5 mol/l. React at 97°C for 5 hours, then filter, wash the filter residue and then roast until the conductivity of the washing water is 100us/cm, roast for 3 hours, and roast at a temperature of 950°C to obtain silicon dioxide.

The crude lead is obtained through smelting-electrolytic refining to obtain a lead plate.

The final recoveries of lead and silicon dioxide were 99.7%, 96.8%, respectively.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (5)

1. The resource processing method of lead-containing glass is characterized in that: comprising the following steps: 1) Breakage of leaded glass. Put the leaded glass into the ball mill and crush it to a particle size of 0.1-1.5mm; 2) Alkali reduction roasting. Mix the crushed lead-containing glass powder with carbon powder and alkali, then granulate it with water, put it into a high-temperature furnace for roasting, the roasting temperature is 300-600°C, and the roasting time is 2-6 hours; 3) Wash and recover lead. Add the roasted material to pure water for slurry, the mass ratio of the roasted material to pure water is 1:5-10, the washing time is 1-5 hours, the washing temperature is 70-100°C, and the 100-300 mesh filter cloth is used after washing Filtration, the filter residue is crude lead; 4) Recovery of silica. Add acid to the water-washed filtrate to adjust the pH to 0.5-4.5, react at 70-99°C for 1-5 hours, then filter, wash the filter residue and roast for 1-5 hours at a roasting temperature of 500-1000°C to obtain di silicon oxide. 2. The recycling method of lead-containing glass according to claim 1, characterized in that: the mass ratio of lead-containing glass powder, carbon powder, and alkali in the step 2 is 1:0.5-1.5:0.5-1.0, The alkali is at least one of sodium hydroxide, barium hydroxide and potassium hydroxide. 3. The method for resourceful treatment of lead-containing glass according to claim 1, characterized in that: the acid in the step 4 is at least one of sulfuric acid, hydrochloric acid, nitric acid, and acetic acid, and the concentration of the acid is 5-10mol/ l. 4. The method for recycling lead-containing glass according to claim 1, characterized in that: the crude lead is smelted-electrolytically refined to obtain a lead plate. 5 . The method for recycling lead-containing glass according to claim 1 , characterized in that: the washing until the conductivity of the washing water is less than 200 us/cm. 6 .