阅读说明：本技术 一种微波热力熔炼处理废弃含铅玻璃的方法 (Method for treating waste lead-containing glass by microwave thermal smelting ) 是由 王俊鹏 陈裕瀚 刘畅 张德琦 冯锡炜 于 2021-10-20 设计创作，主要内容包括：本发明属于电子废弃物循环利用领域,特别涉及一种微波热力熔炼处理废弃含铅玻璃的方法,包括：(1)将从家电拆解企业得到的废弃含铅玻璃磨成粉；(2)将废弃含铅玻璃、氧化亚铁、碳粉和氧化钙按照一定比例混合均匀；(3)将混合好的物料放入到微波炉中进行高温熔炼,熔炼结束后,让物料自然冷却至室温,分离出下层粗铅和上层还原渣。利用微波熔炼方法,将废弃含铅玻璃与助剂进行混合还原,充分利用微波的选择性加热、内热源加热和体加热的特点,降低反应温度,缩短工艺时间,进而降低处理废弃含铅玻璃的能耗成本,并且实现了废弃含铅玻璃的无害化处理。(The invention belongs to the field of recycling of electronic wastes, and particularly relates to a method for treating waste lead-containing glass by microwave thermal smelting, which comprises the following steps: (1) grinding waste lead-containing glass obtained from household appliance dismantling enterprises into powder; (2) uniformly mixing the waste lead-containing glass, ferrous oxide, carbon powder and calcium oxide according to a certain proportion; (3) and (3) putting the mixed material into a microwave oven for high-temperature smelting, naturally cooling the material to room temperature after smelting is finished, and separating the lower-layer crude lead and the upper-layer reducing slag. The waste lead-containing glass and the auxiliary agent are mixed and reduced by using a microwave smelting method, the characteristics of selective heating, internal heat source heating and body heating of microwaves are fully utilized, the reaction temperature is reduced, the process time is shortened, the energy consumption cost for treating the waste lead-containing glass is further reduced, and the harmless treatment of the waste lead-containing glass is realized.)

1. A method for treating waste lead-containing glass by microwave thermal smelting is characterized by comprising the following steps:

(1) grinding the waste lead-containing glass into powder;

(2) uniformly mixing the ground waste lead-containing glass powder with ferrous oxide, carbon powder and calcium oxide;

(3) and putting the mixed materials into a microwave oven, carrying out high-temperature smelting in an inert atmosphere, naturally cooling to room temperature after smelting is finished, and separating lower-layer crude lead and upper-layer reducing slag.

2. The method for treating the waste lead-containing glass by microwave thermal smelting according to claim 1, wherein in the step (1), the waste lead-containing glass is ground to a particle size of less than 0.074mm, and the particle size of the carbon powder is less than 0.074 mm.

3. The method for treating the waste lead-containing glass by microwave thermal smelting according to claim 1, wherein the mass percentage of PbO in the waste lead-containing glass in the step (1) is 20-30%.

4. The method for treating the waste lead-containing glass by microwave thermal smelting according to claim 1, wherein the ferrous oxide is added in the step (2) in an amount of 20-40% of the mass of the waste lead-containing glass; the addition amount of the calcium oxide is 5 to 15 percent of the mass of the waste lead-containing glass; the molar ratio of the carbon powder to PbO in the waste lead-containing glass is 1-1.5: 1.

5. the method for treating the waste lead-containing glass through microwave thermal smelting according to claim 1, wherein the microwave heating power in the smelting process in the step (3) is 4-6 kW, the heating temperature is 1200-1350 ℃, and the heating time is 40-60 min.

6. The method for treating the waste lead-containing glass by microwave thermal smelting according to claim 1, wherein the inert atmosphere in the step (3) is nitrogen.

7. The method for treating the waste lead-containing glass by microwave thermal smelting according to claim 1, wherein the mass percentage of lead in the crude lead obtained by the method is more than 98%, and the lead recovery rate is more than 95%.

Technical Field

The invention belongs to the field of recycling of electronic wastes, and particularly relates to a method for treating waste lead-containing glass by microwave thermal smelting.

Background

Lead-containing glass is widely used for producing cathode ray tubes of displays and televisions, but with the development of science and technology, the living standard of people is continuously improved, the updating speed of display products is accelerated, and a large number of cathode ray tube displays enter a scrapping treatment stage. In addition, there are also a large number of discarded cathode ray tube electronic devices that are transported from developed countries to China through illegal routes. Therefore, the recycling of lead-containing glass in the electronic products of the waste cathode ray tubes becomes a problem which is urgently needed to be solved in China.

At present, the treatment mode aiming at the waste lead-containing glass mainly focuses on four aspects of being used as a metal smelting fluxing agent, producing radiation-proof glass, solidifying and burying, preparing foam glass and the like. The waste lead-containing glass is used as a metal smelting fluxing agent to replace a metallurgical fluxing agent, but the content of alkali metals such as potassium, sodium and the like in the lead-containing glass is high, and the lead-containing glass seriously corrodes a refractory material in the smelting process; the content of lead in the radiation-proof glass is more than 60 percent, and the waste lead-containing glass contains a large amount of lead, so that the waste lead-containing glass is feasible for producing a nuclear waste packaging material and a radiation shielding device, but the waste lead-containing glass cannot be a main recycling method because the treatment capacity of the waste lead-containing glass is very limited; the waste lead-containing glass is treated in a solidifying and burying way, not only is lead resource wasted, but also potential environmental risks exist, so that the waste lead-containing glass is treated in a burying way to the greatest extent; the production of foam glass is the primary area of research in the current recycling of waste leaded glass and although researchers have made some progress in this area, their use has been somewhat limited due to the lack of consideration of the environmental hazards of lead in the foam material.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for treating waste lead-containing glass by microwave thermal smelting.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for treating waste lead-containing glass by microwave thermal smelting comprises the following steps:

(1) grinding the waste lead-containing glass into powder;

(2) uniformly mixing the ground waste lead-containing glass powder with ferrous oxide, carbon powder and calcium oxide;

(3) and putting the mixed materials into a microwave oven, carrying out high-temperature smelting in an inert atmosphere, naturally cooling to room temperature after smelting is finished, and separating lower-layer crude lead and upper-layer reducing slag.

Further, the waste lead-containing glass in the step (1) is ground until the grain size is less than 0.074mm, and the grain size of the carbon powder is less than 0.074 mm.

Further, the mass percentage of PbO in the waste lead-containing glass in the step (1) is 20-30%.

Further, the adding amount of the ferrous oxide in the step (2) is 20-40% of the mass of the waste lead-containing glass; the addition amount of the calcium oxide is 5 to 15 percent of the mass of the waste lead-containing glass; the molar ratio of the carbon powder to PbO in the waste lead-containing glass is 1-1.5: 1.

further, the microwave heating power in the smelting process in the step (3) is 4-6 kW, the heating temperature is 1200-1350 ℃, and the heating time is 40-60 min.

Further, the inert atmosphere in the step (3) is nitrogen.

Furthermore, the mass percentage of lead in the crude lead obtained by the method is more than 98%, and the lead recovery rate is more than 95%.

Compared with the prior method for treating the waste lead-containing glass, the method has the following beneficial effects:

(1) mixing and reducing the waste lead-containing glass and an auxiliary agent by using a microwave smelting method, adding carbon powder into the lead-containing glass, reducing lead oxide in the lead-containing glass in a microwave heating mode, reducing the lead oxide in the glass by using CO gas generated by a Boolean reaction to generate lead bullion, wherein the chemical equation of the reaction is PbO & SiO₂(l)+FeO(s)+CO(g)＝2FeO·SiO₂(l) + Pb (l) + CO (g) to realize the harmless treatment of the lead-containing glassTherefore, the purpose of changing waste into valuable is achieved.

(2) Lead oxide and carbon powder in the lead-containing glass belong to strong wave-absorbing substances and can be rapidly heated in a microwave field, so that the nucleation time of lead crystal grains is shortened in the reduction process, the rapid growth of the size of the lead crystal grains is promoted, and the recovery rate of lead in the lead-containing glass is improved.

(3) The characteristics of selective heating, internal heat source heating and body heating of the microwave are fully utilized, the reaction temperature of the reduction reaction can be reduced, the process time is shortened, and the energy consumption cost for treating the waste lead-containing glass is further reduced.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The chemical compositions of the lead-containing glass discarded in the examples of the present invention are shown in Table 1.

Table 1 chemical composition of lead-containing glass discarded in examples (mass fraction,%)

In the embodiment of the invention, the ferrous oxide, the calcium oxide and the carbon powder are analytically pure, and the particle size of the carbon powder is less than 0.074 mm.

Example 1

A method for treating waste lead-containing glass by microwave thermal smelting comprises the following steps:

(1) grinding waste lead-containing glass obtained from household appliance dismantling enterprises to the particle size of less than 0.074 mm;

(2) weighing 1000g of waste lead-containing glass powder, 210g of ferrous oxide, 16g of carbon powder and 80g of calcium oxide, and fully and uniformly mixing;

(3) and (2) putting the mixed material into a microwave oven for high-temperature smelting, wherein the microwave heating power is 4kW, the heating temperature is 1200 ℃, the heating time is 60min, nitrogen is introduced during the smelting process, the material is naturally cooled to room temperature after the smelting is finished, the lower-layer crude lead and the upper-layer reducing slag are separated, the mass percentage content of lead in the obtained crude lead is 98.23%, and the lead recovery rate is 95.78%.

Example 2

A method for treating waste lead-containing glass by microwave thermal smelting comprises the following steps:

(1) grinding waste lead-containing glass obtained from household appliance dismantling enterprises to the particle size of less than 0.074 mm;

(2) weighing 800g of waste lead-containing glass powder, 160g of ferrous oxide, 12g of carbon powder and 40g of calcium oxide, and fully and uniformly mixing;

(3) and (3) putting the mixed material into a microwave oven for high-temperature smelting, wherein the microwave heating power is 5kW, the heating temperature is 1300 ℃, the heating time is 45min, nitrogen is introduced during the smelting process, the material is naturally cooled to room temperature after the smelting is finished, the lower-layer crude lead and the upper-layer reducing slag are separated, the mass percentage content of lead in the obtained crude lead is 98.98%, and the lead recovery rate is 96.17%.

Example 3

A method for treating waste lead-containing glass by microwave thermal smelting comprises the following steps:

(1) grinding waste lead-containing glass obtained from household appliance dismantling enterprises to the particle size of less than 0.074 mm;

(2) weighing 500g of waste lead-containing glass powder, 200g of ferrous oxide, 10g of carbon powder and 75g of calcium oxide, and fully and uniformly mixing;

(3) and (3) putting the mixed material into a microwave oven for high-temperature smelting, wherein the microwave heating power is 6kW, the heating temperature is 1350 ℃, the heating time is 40min, nitrogen is introduced in the smelting process, after the smelting is finished, the material is naturally cooled to the room temperature, the lower-layer crude lead and the upper-layer reducing slag are separated, the mass percentage content of lead in the obtained crude lead is 98.56%, and the lead recovery rate is 96.79%.

Example 4

A method for treating waste lead-containing glass by microwave thermal smelting comprises the following steps:

(1) grinding waste lead-containing glass obtained from household appliance dismantling enterprises to the particle size of less than 0.074 mm;

(2) weighing 1200g of waste lead-containing glass powder, 350g of ferrous oxide, 21g of carbon powder and 120g of calcium oxide, and fully and uniformly mixing;

(3) and (3) putting the mixed material into a microwave oven for high-temperature smelting, wherein the microwave heating power is 5kW, the heating temperature is 1250 ℃, the heating time is 50min, nitrogen is introduced during the smelting process, the material is naturally cooled to room temperature after the smelting is finished, the lower-layer crude lead and the upper-layer reducing slag are separated, the mass percentage content of lead in the obtained crude lead is 98.83%, and the lead recovery rate is 96.28%.

The technical idea of the present invention is described in the above technical solutions, and the protection scope of the present invention is not limited thereto, and any changes and modifications made to the above technical solutions according to the technical essence of the present invention belong to the protection scope of the technical solutions of the present invention.