CN110526642A - A kind of cement solidification method of mixed burning waste residue - Google Patents

Abstract

The invention discloses a cement solidification method for mixed incineration waste slag, which comprises the following steps: (1) Take a certain quality of mixed incineration waste slag, add oxidant and water, stir for a certain period of time, then add a stabilizer, and continue stirring for a certain period of time; (2) ) Add several parts of fly ash and bistrimethylsilyl hydrogen phosphate to the mixed slurry obtained in step (1), and stir for a certain period of time; (3) Add some parts to the mixed slurry obtained in step (2) Portland cement, sodium lignin sulfonate, biomass-based solid acid and glass fiber, then add appropriate amount of water, stir until uniform, and place it at room temperature for a certain period of time to obtain a solidified body; (4) Take water to pour the solidified body The leaching rate of solidified heavy metals prepared by this curing method is low, which meets the limit value of hazardous waste allowed to enter the landfill specified in the "Hazardous Waste Landfill Pollution Control Standard", and realizes the centralized treatment of mixed incineration waste residues. Significance.

Description

A kind of cement solidification method of mixed incineration waste residue

technical field

The invention relates to the field of incineration waste residue treatment, in particular to a cement solidification method for mixing incineration waste residue.

Background technique

Incineration treatment of hazardous wastes can not only reduce the volume of hazardous wastes in the environment, but also transform and reduce the harmful components in hazardous wastes. It is a method commonly used at home and abroad to treat hazardous wastes. However, the incineration of hazardous waste may produce a series of secondary pollution, such as smoke, nitrogen oxides, sulfur oxides, and incineration residues generated during the incineration process. Cement solidification of hazardous waste incineration residues is a common method for treating hazardous waste incineration residues at home and abroad.

In accordance with national standards, a class of wastes identified that have at least one of the five hazardous characteristics of corrosiveness, toxicity, flammability, reactivity, and infectivity or that are included in the national list of hazardous wastes and may endanger the environment or human health called hazardous waste. Hazardous waste incineration slag refers to selected hazardous waste that can be used for incineration treatment. It is burned under incineration conditions such as controlled oxygen and hazardous waste, and an oxidation reaction occurs. The resulting residue is called hazardous waste incineration slag. Cement solidification of hazardous waste incineration residue can not only reduce the concentration of harmful components, but also lower operating costs, the operation process is relatively simple, and the solidified block is stable. But for now, there are still some technical problems in cement solidification of incineration waste. For example, due to the different components of cement solidified waste residue, it is necessary to reasonably adjust the composition of the curing agent, otherwise the solidified body will have low curing strength, causing the solidified body to collapse twice under certain circumstances, such as high pressure, resulting in pollution. secondary diffusion. Since there are often some heavy metal residues in the incineration waste residue, there is a problem of heavy metal leaching during the stacking process of the solidified body. In addition, because the cement curing method needs to use a large amount of cement for curing, the cement has a large alkalinity, and some alkaline additives are often added to the cement curing additives to treat heavy metals, which often leads to the alkalinity of the leachate of the waste residue exceeding the standard, which does not meet the requirements. Corresponding waste landfill standard "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)". For cement curing additives, the currently used composite additives are usually added at one time, which has a certain impact on the effective function of the additive.

Contents of the invention

The purpose of the invention of the present invention is to solve the above-mentioned technical problems existing in the prior art,

In order to achieve the above object, the present invention adopts the following technical solutions:

A cement solidification method for mixing incineration waste slag, comprising the following steps:

(1) According to the number of parts by mass, take 100 parts of mixed incineration waste residue, add 1-8 parts of oxidant, add 80-160 parts of water, stir for 5-20 minutes, then add 5-20 parts of stabilizer, continue stirring for 20-60 minute;

(2) Continue to add 20-50 parts of fly ash and 1-3 parts of bistrimethylsilyl hydrogen phosphate to the mixed slurry obtained in step (1), and stir for 5-10 minutes;

(3) Add 30-60 parts of Portland cement, 5-15 parts of sodium lignosulfonate, 10-25 parts of biomass-based solid acid and 5-12 parts of glass fiber to the mixed slurry obtained in step (2) , then add 30-70 parts of water, stir until evenly placed at room temperature for 10-24 hours to obtain a cured body;

(4) Take water according to 10-15% of the weight of the solidified body to carry out pouring maintenance on the solidified body, twice a day, and the curing period is 5-15 days.

Further, the oxidizing agent is selected from potassium permanganate, potassium persulfate, sodium persulfate or ammonium persulfate.

Further, the mixed incineration waste is a mixture of organic solvent incineration waste, mineral oil incineration waste, surface treatment agent incineration waste, medical waste incineration waste and waste paint incineration waste.

Further, the stabilizer is selected from one or more of sodium hydrosulfide, potassium sulfide, sodium sulfide, sodium thiosulfate or potassium hydrosulfide.

Further, the stabilizer is sodium thiosulfate.

Further, the sour sites of the biomass-based solid acid are not less than 0.5 mol/g. For biomass-based solid acid catalysts, a variety of methods can be used to prepare, such as pyrolysis-sulfonation method, the crushed biomass raw materials, such as wood, straw, etc. are dried, and then pyrolyzed at high temperature under inert gas to form Biomass charcoal, sulfonate the above biomass charcoal in concentrated sulfuric acid, wash with deionized water and then dry to obtain the desired biomass solid acid. Of course, the corresponding biomass solid acid can also be obtained by treating the biomass material through other methods disclosed in the prior art.

The beneficial effects of the present invention are:

In order to achieve the fixation of heavy metals in the incineration waste residue, the oxidant is fully oxidized in the waste residue, on the one hand, it is beneficial to the solidification between the waste residue itself and subsequent additives, such as fly ash and cement, and the waste residue, and more importantly, It is beneficial to The heavy metal stabilizer added later will form corresponding hydroxide complexes with the heavy metals in the waste residue, which is very effective in preventing the leaching of heavy metals in the waste residue. By adding biomass solid acid, the pH value of the leaching solution of the solidified body can be effectively regulated during the oxidation process of the solidified body. By exploring the order of adding additives and optimizing the proportion of additives added, the requirements of the national stacking standard for cement curing can be met.

Detailed ways

The present invention will be further described below by specific embodiment

The mixed incineration waste treated by the present invention is taken from Ma'anshan Hazardous Waste Centralized Disposal Center.

Example 1

A cement solidification method for mixing incineration waste slag, comprising the following steps:

(1) According to the number of parts by mass, take 100 parts of mixed incineration waste residue, add 1 part of potassium permanganate, add 100 parts of water, stir for 5-20 minutes, then add 5 parts of sodium thiosulfate, and continue stirring for 20 minutes;

(2) Continue to add 20 parts of fly ash and 2 parts of bistrimethylsilyl hydrogen phosphate to the mixed slurry obtained in step (1), and stir for 5-10 minutes;

(3) Add 30 parts of Portland cement, 5 parts of sodium lignosulfonate, 10 parts of biomass-based solid acid with an acid site of 0.5 mol/g and 8 parts of glass fiber to the mixed slurry obtained in step (2). part, then add 50 parts of water, stir until uniform, and place it at room temperature for 10 hours to obtain a cured body;

(4) Take water according to 10% of the weight of the solidified body to carry out pouring maintenance on the solidified body, twice a day, and the curing period is 5 days.

Considering the leaching toxicity of the solidified body of mixed incineration waste residues transported to landfills for landfill under acidic conditions, and analyze whether the solidified blocks formed by this solidification process will produce secondary pollution under conditions such as acid rain . Here, the sulfuric acid-nitric acid method is used to carry out the leaching experiment on the original sample, the sample after curing, the sample after curing, cement, etc., and add the pre-configured concentrated sulfuric acid and concentrated nitric acid mixture into the ultrapure water to adjust the pH to make the pH between 3.15- Between 3.25. Weigh 5 g of the relevant sample, add the required extractant according to the liquid-solid ratio of 10:1, tighten the cap of the bottle and fix it on an inversion oscillator, and set the oscillation time to 18 h. After the shaking is over, remove the bottle and filter it on a 0.6-0.8um filter membrane using a high-pressure filter device to obtain a clear liquid that is the leachate. Immediately filter the leached liquid through a filter membrane with a diameter of 0.45 um, and measure its pH value with a pH meter. An appropriate amount of nitric acid is added to the leached solution to adjust the pH<2.0, and then the metal content in each leached solution is directly measured with a plasma emission spectrometer.

It can be known from the detection of the leachate by the above method that after solidification by the method of Example 1, the original leaching value of each metal in the leachate meets the requirements in the "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)" that hazardous waste is allowed to enter the landfill area The control limit of which the pH value of leaching is 10.

Example 2

Refer to the steps in Example 1 to solidify the mixed incineration waste residue. The difference is that the oxidant in step (1) uses 2 parts of ammonium persulfate, and the acid site of biomass solid acid in step (3) is 1.3 mol/ g.

After solidification by the method in Example 2, the original leaching value of each metal in the leach solution meets the control limit for hazardous wastes allowed to enter the landfill specified in the "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)", wherein the leaching of pH The value is 9.

Example 3

The mixed incineration waste residue was solidified with reference to the steps in Example 1, except that the amount of glass fiber added in step (3) was 12 parts.

After solidification by the method in Example 3, the original leaching value of each metal in the leach solution meets the control limit for hazardous wastes allowed to enter the landfill specified in the "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)", wherein the leaching of pH The value is 10. Compared with Example 1, the strength of the cured body in this example has been improved by 23%, which can meet the landfill requirements of the landfill.

Example 4

The mixed incineration waste was solidified with reference to the steps in Example 1, except that the curing period in step (4) was 10 days.

After solidification by the method in Example 2, the original leaching value of each metal in the leach solution meets the control limit for hazardous wastes allowed to enter the landfill specified in the "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)", wherein the leaching of pH The value is 9. It can be seen that as the curing time increases, it is beneficial to the acid-base balance of the cured body.

Comparative example 1

The mixed incineration waste residue was solidified with reference to the steps in Example 1, except that no biomass-based solid acid was added in step (3).

After being solidified by the method of Comparative Example 1, the original leaching value of each metal in the leachate of the solidified body meets the control limit for hazardous wastes allowed to enter the landfill specified in the "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)", but The pH leach value was 13, exceeding the landfill entry criteria (7-12).

Comparative example 2

Refer to the steps in Example 1 to solidify the mixed incineration waste residue, the difference is that step (2) is omitted, and 20 parts of fly ash and 2 parts of bistrimethylsilyl hydrogen phosphate are mixed with step (3) silicon Salt cement and other raw materials are added at the same time.

After solidification by the method of Comparative Example 2, the leaching values of lead, zinc and chromium in the leachate of the cured body exceeded 23% of the heavy metal limits stipulated in the "Hazardous Waste Landfill Pollution Control Standard (GB18598-2001)", 65 and 34%.

The above are only preferred specific implementations of the present invention. These specific implementations are all based on different implementations under the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field Within the technical scope disclosed in the present invention, any changes or substitutions that can be easily conceived by a skilled person shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (6)

1. a kind of cement solidification method of mixed burning waste residue, which comprises the following steps:

(1) according to mass fraction meter, 100 parts of mixed burning waste residue are taken, is added oxidant 1-8 parts, is added water 80-160 parts, stirring 5-20 minutes, it is then added stabilizer 5-20 parts, continues stirring 20-60 minutes；

(2) it obtains continuously adding 20-50 parts of flyash, double trimethyl silicon substrate hydrogen phosphate 1-3 in mixed slurry in step (1) Part, it stirs 5-10 minutes；

(3) it obtains that portland cement 30-60 parts, 5-15 parts of sodium lignin sulfonate, biology are added in mixed slurry in step (2) Then plus 30-70 parts of water 10-25 parts of matter based solid acid and glass fibre 5-12 part, in room temperature environment placement after being stirred until homogeneous Solidified body is obtained after 10-24h；

(4) fetch water according to the 10-15% for solidifying body weight and pour leaching maintenance to solidified body, twice daily, curing cycle 5-15 It.

2. a kind of cement solidification method of mixed burning waste residue according to claim 1, it is characterised in that: the oxidant Selected from potassium permanganate, potassium peroxydisulfate, sodium peroxydisulfate or ammonium persulfate.

3. a kind of cement solidification method of mixed burning waste residue according to claim 1, it is characterised in that: the mixing is burnt Burn waste residue be organic solvent burn waste residue, mineral oil burn waste residue, surface treating agent burn waste residue, medical refuse burning waste residue and The mixture of waste oil paint burning waste residue.

4. a kind of cement solidification method of mixed burning waste residue according to claim 1, it is characterised in that: the stabilizer Selected from NaHS, one or more of potassium sulfide, vulcanized sodium, sodium thiosulfate or potassium bisulfide.

5. a kind of cement solidification method of mixed burning waste residue according to claim 4, it is characterised in that: the stabilizer For sodium thiosulfate.

6. a kind of cement solidification method of mixed burning waste residue according to claim 1, it is characterised in that: the biomass The acidic site of based solid acid is not less than 0.5mol/g.