CN103922674A - Method for producing light-weight wall material by using papermaking white clay - Google Patents

Abstract

The invention relates to a method for producing a light-weight wall material by using papermaking white clay. The method comprises the steps of preparing the following components in percentage by mass: 60-70% of papermaking white clay, 5-10% of zirconium-silicate slag, 20-30% of Portland cement and 1-5% of an enhanced water-releasing agent and mixing uniformly, preparing into concrete slurry having a required flowability, curing and molding, wherein the enhanced water-releasing agent is a mixed solution prepared by dissolving 4-5 parts of sodium sulfate, 7-8 parts of triethanolamine, 15-18 parts of saccharide sodium, 25-30 parts of sodium methyl sulfonate and 40-45 parts of calcium lignin sulfonate in water. The wall material prepared by the method disclosed by the invention has the advantages of good compressive strength, good heat insulation property, low density and light self-weight.

Description

A method for producing light wall material with papermaking white mud

technical field

The invention relates to a method for producing light-weight wall materials with papermaking white mud, and belongs to the technical fields of waste utilization and building materials.

Background technique

According to the data of China Paper Association, as of the end of 2012, my country's paper and cardboard production and consumption have surpassed the United States for three consecutive years, ranking first in the world, reaching 99.3 million tons, and paper production and consumption accounted for 23.3% of the world's total. % and 23.1%.

Shandong Province is a major paper-making province, with an output of 17.1 million tons in 2012, accounting for 17% of the country's total output, ranking first in the country for 18 consecutive years. While vigorously developing paper-making enterprises in our province, the water pollution problem in the paper-making industry has been improved to a certain extent, but white mud pollution will increasingly become an important environmental bottleneck affecting the development of paper-making enterprises. In October 2013, the Environmental Protection Department of Shandong Province held an on-site meeting on the treatment and comprehensive utilization of white mud from papermaking in Weifang, pointing out that due to the limitations of processing costs and technology, except for some enterprises in our province that have recycled white mud, most enterprises just choose places to fill Buried or stacked. This not only wastes a lot of limestone resources, but also causes serious secondary pollution to the surrounding soil and groundwater resources. Due to the shortage of land resources, landfill disposal is becoming more and more difficult, and the white mud piled up in the open air will also form a source of dust pollution, which will affect air quality. It is required to strengthen the management and supervision of white mud, improve resource utilization, reduce or even eliminate white mud discharge, and ensure environmental safety.

According to the existing technology, about 1 ton of lime mud is produced for every 1 ton of pulp produced, and with the increase in the number and scale of alkali recovery systems newly built by pulp and paper enterprises in my country, the produced lime mud will increase and accumulate in a large proportion.

Pulp and paper white mud (hereinafter referred to as white mud) is a muddy sediment by-product produced in the causticizing process of the paper industry. Its main chemical reaction formula is as follows:

Na ₂ CO ₃ +Ca(OH) ₂ →CaCO ₃ ↓+2NaOH

After the causticized emulsion is clarified, the sodium hydroxide solution (white liquor) is separated and stored for recycling in pulping and cooking; the precipitated white mud is further washed and filtered to recover the sodium hydroxide, and finally obtain a waste residue with a high moisture content . At present, most enterprises use landfill or stacking to dispose of paper-making white mud. Although landfill treatment is simple and easy, and requires less investment, it needs to occupy a large amount of land resources. Due to the decomposition of microorganisms and microorganisms, high-concentration leachate and the dissolution of residual alkali will be produced, causing groundwater pollution. At the same time, there is still a risk of collapse of large lime mud yards under severe weather conditions, which has become a hidden danger of social harm. Therefore, this extensive white mud treatment method not only brings hidden dangers of environmental pollution, waste of resources, and social hazards, but also has become a constraint for the sustainable development of enterprises with the rising cost of land, management and maintenance, and increasingly stringent environmental protection requirements. As one of the important factors, it is an inevitable choice for papermaking enterprises and the whole society to seek resource recovery and utilization of lime mud.

The main mineral component of white mud is poorly crystallized CaCO ₃ , with a particle size of 15-25 μm. It is a loose, porous, and fine-grained solid waste. Generally, the moisture content of papermaking lime mud is 25-30%, and some papermaking fibers and some organic matter remain.

Chinese invention patent 201210105925.3 "Method for producing autoclaved lime-sand bricks by using paper-making white mud", firstly dehydrate the white mud to a water content of 30-35%, then send the white mud to the drum dryer, and dry it with hot air When the water content is less than 10%, it is stirred with other conventional raw materials of autoclaved lime-sand bricks and then sent to the digestion bin. The amount of dry white mud accounts for 10-50% of the total brick-making amount. After digesting for four hours, it is then stirred After uniformity, it is sent to the silo, and bricks are made into bricks with a brick press machine, and they are stacked on the track trolley, and transported to the autoclave. , curing for eight hours, drying the lime mud, the preparation process is complicated, and the cost is high.

Patent CN102432241A discloses a method of using papermaking lime mud to produce wall materials. The weight percentages are 40-60% paper-making lime mud, 20-45% lithium slag, 10-20% cement and 1-6% The active activator is added into the mixer and mixed; the mixed material is divided into a group of molds, and placed on the vibrating table of the block forming machine for vibration molding; the active activator is composed of polyacrylic acid, polycarboxylate water reducer It is mixed with aluminum potassium sulfate; then put the mold containing the mixed material in a curing box with a temperature of 15-25°C and a humidity of >90% for 20-30 hours, then release the mold, and then put it in a temperature of 60-80°C Steamed in the curing box for 20 to 30 hours, that is, the wall material product is obtained. Although the wall material with qualified performance is prepared by adopting the present invention, the maintenance process of this method is relatively complicated and the production cost is relatively high.

Lightweight concrete is a new type of building energy-saving material that is waste-recycling, environmentally friendly, energy-saving, inexpensive and non-combustible. Lightweight concrete (also known as foam concrete) is formed by introducing air or nitrogen, carbon dioxide, oxygen and other gases into the concrete slurry according to the application needs through chemical or physical methods, and after reasonable maintenance and molding, it is formed with a large number of small closed pores. , and has a considerable strength of concrete products. The production of lightweight concrete is usually prepared by mechanical means to prepare foaming agent aqueous solution into foam. The preparation process and cost of lightweight concrete are relatively high.

If papermaking waste can be rationally utilized and used in the preparation of lightweight materials, it will not only reduce environmental pollution, but also reduce the production cost of lightweight materials and improve performance, which will have obvious social and economic benefits.

Contents of the invention

Aiming at the problems of existing paper-making white mud polluting the environment and high production cost of lightweight concrete, the present invention proposes a method for producing light-weight wall materials with paper-making white mud, so as to achieve the goals of energy saving, emission reduction and waste utilization.

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

A method of producing light wall material with papermaking white mud:

According to the mass percentage of 60-70% papermaking white mud, 5-10% zirconium silica slag, 20-30% Portland cement, 1-5% enhanced water-releasing agent, take materials and mix them evenly to form fluidity Concrete slurry that reaches the requirements is maintained and formed; the enhanced water-releasing agent is 4-5 parts by weight of sodium sulfate, 7-8 parts of triethanolamine, 15-18 parts of sodium sugar, and 25-30 parts of methylsulfonate A mixed solution obtained by dissolving sodium lignosulfonate and 40-45 parts of calcium lignosulfonate in water.

The water content of the papermaking white mud is 20-25%, the calcium content is 60-70%, and the residual papermaking fiber is 5-10%.

The zirconium silica slag: it is a colloidal polymer with relatively high water content, and its main component is silicic acid slag (mSiO2·nH2O). The solid content of the zirconium silicon slag is 20±3wt%, the silica content is 12-16wt%, and contains a small amount of zircon sand, sodium metazirconate and the like. Among them, SiO2 is soft and agglomerated in the slag, with large specific surface area and high activity.

The ordinary Portland cement is early-strength 42.5R Portland cement.

The concentration range of the enhanced water-releasing agent solute is 5-10%. The enhanced water release agent is preferably a mixture obtained by mixing 5 parts of sodium sulfate, 7 parts of triethanolamine, 18 parts of sodium sugar, 30 parts of sodium methanesulfonate and 40 parts of calcium lignosulfonate in water by weight. solution.

The present invention has following characteristics and beneficial effect:

(1) Using the present invention, papermaking white mud, zirconium silica slag, cement and enhanced water-releasing agent are mixed to form flocculated sodium silicate solid gel and a large amount of fibrous hydration products, white mud particles in this system , exerting the effect of microcrystalline nucleation and micro-aggregate, filling in the space network formed by the overlapping of fibers and gels, making solid gels and fibers nucleate, crystallize and grow, and playing a role in strengthening the matrix.

(2) A large number of short fibers remaining in the lime mud play a toughening role in the concrete and improve the flexural performance of the lightweight concrete.

(3) White mud and zirconium silica slag have a loose and porous structure. After mixing and curing, they leave evenly closed voids in the concrete, which reduces the density and weight of the concrete.

(4) The use of enhanced water-releasing agent can effectively release the adsorbed water in the lime mud and convert it into free water, which reduces the amount of added water and saves costs; the space left by the water released by the water-releasing agent forms The closed gap also reduces the weight of the product.

(5) The advantage of the present invention is that the large-scale application of industrial waste lime mud not only reduces the environmental load, the manufacturing cost of wall materials, saves a lot of building materials, protects cultivated land, but also achieves the control of environmental pollution and the comprehensive and efficient utilization of waste The double effect promotes the sustainable development of the paper industry and the wall material industry.

(6) The wall material prepared by the method of the present invention has good compressive strength, good heat insulation, low density and light weight.

Detailed ways

Further description below in conjunction with preferred embodiments.

Example 1

Take and mix the materials, take 65% papermaking white mud, 10% zirconium silica slag, 22% ordinary Portland cement, 3% enhanced water release agent, and the enhanced water release agent is 5 parts by weight Sodium sulfate, 7 parts of triethanolamine, 18 parts of sodium sugar, 30 parts of sodium methanesulfonate and 40 parts of calcium lignosulfonate are mixed and dissolved in 900 parts of water to obtain a mixed solution. It is prepared by preparing concrete slurry that meets the requirements of fluidity, natural curing, and its strength and performance are tested for 28 days. The strength grade, water absorption, thermal conductivity, etc. meet the requirements of national standards GB/T15229-2002 and JC/T422-2007.

Example 2

Take and mix the materials, take 68% papermaking white mud, 7% zirconium silica slag, 20% ordinary Portland cement, 5% enhanced water release agent, and the enhanced water release agent is 4 parts by weight Sodium sulfate, 8 parts of triethanolamine, 15 parts of sodium sugar, 25 parts of sodium methanesulfonate and 42 parts of calcium lignosulfonate are mixed and dissolved in 900 parts of water to obtain a mixed solution. It is prepared by preparing concrete slurry that meets the requirements of fluidity, natural curing, and its strength and performance are tested for 28 days. The strength grade, water absorption, thermal conductivity, etc. meet the requirements of national standards GB/T15229-2002 and JC/T422-2007.

Example 3

Take and mix the materials, take 60% papermaking white mud, 7% zirconium silica slag, 30% ordinary Portland cement, 3% enhanced water release agent, and the enhanced water release agent is 5 parts by weight Sodium sulfate, 7 parts of triethanolamine, 17 parts of sodium sugar, 28 parts of sodium methanesulfonate and 45 parts of calcium lignosulfonate are mixed and dissolved in 900 parts of water to obtain a mixed solution. It is prepared by preparing concrete slurry that meets the requirements of fluidity, natural curing, and its strength and performance are tested for 28 days. The strength grade, water absorption, thermal conductivity, etc. meet the requirements of national standards GB/T15229-2002 and JC/T422-2007.

Claims (4)

1. a method of producing light wall material with paper white sludge, is characterized in that,

The enhancing of the silicate cement of the zirconium white residue of the paper white sludge of 60-70%, 5-10%, 20-30%, 1-5% is by mass percentage released aqua feeding and mixes, and is made into mobility and meets the requirements of concrete slurry, maintenance moulding; It is that 4-5 part sodium sulfate, 7-8 part trolamine, 15-18 part sugar sodium, 25-30 part novalgin and 40-45 part calcium lignin sulphonate mix the water-soluble mixing solutions obtaining by weight that aqua is released in described enhancing.

2. a kind of method of producing light wall material with paper white sludge according to claim 1, is characterized in that, described paper white sludge water content is that 20-25%, calcium content are 5-10% at 60-70%, residual paper-making fibre.

3. a kind of method of producing light wall material with paper white sludge according to claim 1, is characterized in that, the concentration range 5-10% of aqua solute is released in described enhancing.

4. a kind of method of producing light wall material with paper white sludge according to claim 1, it is characterized in that, described enhancing is released aqua and is elected 5 parts of sodium sulfate, 7 parts of trolamines, 18 parts of sugared sodium, 30 parts of novalgins and 40 parts of water-soluble mixing solutionss that obtain of calcium lignin sulphonates mixing by weight as.