Treatment method and application of waste gypsum

Abstract

The invention relates to the technical field of gypsum treatment, in particular to a treatment method and application of waste gypsum. A neutral water-containing material and an exciting agent are weighed and prepared according to a preset proportion; adding water into the prepared materials, and stirring to obtain mixed slurry; pressing the mixed slurry in a mold; and demolding and warehousing the pressed mixed slurry. The industrial waste gypsum is taken as a main material, the crystallization property of the gypsum is improved by utilizing a physical excitation technology, so that the influence of various impurities in the gypsum on the performance of a gypsum byproduct is reduced, and meanwhile, slag with potential activity in the industrial waste gypsum is activated by utilizing the excitation technology; the high-density material is prepared through a process equipment means of combining high pressure and vacuum negative pressure, the industrial waste gypsum raw material is not fried, secondary pollution is not generated, and the cost is effectively reduced. Therefore, the problem that an existing waste gypsum treatment method is large in pollution is solved.

Description

Technical Field

[0001] The invention relates to the technical field of gypsum treatment, and in particular to a method for disposing of waste gypsum and application thereof. Background Art

[0002] The current mainstream application of industrial waste gypsum is: first, through low-temperature or high-temperature calcination, grinding, aging and other disposal processes, the industrial waste gypsum is turned into semi-hydrated gypsum, which has a certain activity, and then combined with silicate cement, mineral powder, special admixtures and other substances in a certain proportion and mixed and stirred to produce related building materials (leveling, flooring, decorative plastering, etc.) for production related construction.

[0003] The calcination process consumes energy and generates secondary pollution. The instability of industrial waste gypsum makes the calcined hemihydrate gypsum unstable, resulting in instability of the product. Due to the characteristics of hemihydrate gypsum, the materials produced by this process are not water-resistant, which affects the application of the product.

[0004] In recent years, the application research of industrial waste gypsum as an activator and retarder in cement and concrete has attracted much attention, but most of them remain in the laboratory stage, and further practical production applications need to be vigorously promoted.

[0005] The current treatment method for industrial waste gypsum is accumulation (for example, about 20 million tons are accumulated in Xifeng, Guizhou). However, accumulation will have an impact on the surrounding environment, pollute the water body, and harm the ecology. At the same time, enterprises also face great environmental pressure. Summary of the invention

[0006] The purpose of the present invention is to provide a method for disposing waste gypsum and application thereof, aiming to solve the problem of serious pollution caused by the existing method for disposing waste gypsum.

[0007] To achieve the above object, in a first aspect, the present invention provides a method for disposing waste gypsum, comprising the following steps:

[0008] Pre-treating the waste gypsum to obtain a neutral water-containing material;

[0009] The neutral water-containing material and the stimulant are weighed and prepared according to a preset ratio;

[0010] Adding water to the prepared materials and stirring to obtain a mixed slurry;

[0011] Putting the mixed slurry into a mold for pressing;

[0012] The mixed slurry after pressing is demoulded and stored.

[0013] Among them, in "pre-treating the waste gypsum to obtain a neutral water-containing material", the pre-treatment includes mixing, stirring, comprehensive mixing of peracid and alkali, and molding.

[0014] Among them, in “the neutral water-containing material and the stimulant are weighed and prepared according to a preset ratio”, the proportion of the neutral water-containing material is greater than 55%, and the proportion of the stimulant is less than 20%.

[0015] The step of “placing the mixed slurry into a mold for pressing” includes the following steps:

[0016] Put the mixed slurry into the mold for pre-pressing;

[0017] The material after the primary pre-pressing is subjected to secondary pressing and molding.

[0018] In a second aspect, a method for disposing of waste gypsum is used, which adopts the method for disposing of waste gypsum described in the first aspect and is applied to the treatment of waste gypsum to achieve recycling.

[0019] A method for disposing waste gypsum of the present invention comprises the following steps: pre-treating the waste gypsum to obtain a neutral water-containing material; weighing and preparing the neutral water-containing material and an activator according to a preset ratio; adding water to the prepared material and stirring it to obtain a mixed slurry; placing the mixed slurry in a mold for pressing; demolding the pressed mixed slurry and storing it. The present invention uses industrial waste gypsum as the main material, and uses physical excitation technology to improve the crystallization properties of gypsum to reduce the influence of various impurities in the gypsum on the performance of gypsum by-products. At the same time, the excitation technology activates the potentially active slag in the industrial waste gypsum. A high-density material is prepared by a process equipment means combining high pressure with vacuum negative pressure, without frying the industrial waste gypsum raw materials, and without generating secondary pollution, which effectively reduces the cost. Thus, the problem of large pollution in the existing method for disposing waste gypsum is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a gypsum sample processed by pouring molding method.

[0022] Figure 2 It is a gypsum sample formed under 600-1500 tons of pressure.

[0023] Figure 3 These are the results of experiments on finished plaster.

[0024] Figure 4 It is a test report on the finished gypsum.

[0025] Figure 5 The present invention is a flowchart of a method for disposing of waste gypsum.

[0026] Figure 6 It is a flow chart of putting the mixed slurry into a mold for pressing.

[0027] Figure 7 It is a production process flow chart. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] See also Figures 1 to 7 In a first aspect, the present invention provides a method for disposing waste gypsum, comprising the following steps:

[0030] S1 pre-treats the waste gypsum to obtain a neutral water-containing material;

[0031] The pretreatment includes mixing and stirring, comprehensive mixing of peracid and alkali, and molding.

[0032] Specifically, the industrial waste gypsum in the original solid and sludge state is forced to mix and stir through a forced device that uses a flying knife and a high-speed rotating combination, and then mixed with acid and alkali to form a neutral water-containing material, and then through a homogenization process to form a stable basic material that can be used for production. It mainly solves the acidity and instability of industrial waste gypsum.

[0033] S2: weighing and preparing the neutral water-containing material and the stimulant according to a preset ratio;

[0034] The proportion of the neutral water-containing material is greater than 55%, and the proportion of the activator is less than 20%.

[0035] Specifically, the homogenized neutral water-containing material (the parameter amount is greater than 55%) and the stimulant (less than 20%) are weighed and proportioned.

[0036] S3: adding water to the prepared material and stirring to obtain a mixed slurry;

[0037] Specifically, the weighed and prepared materials are sent to a single-axis double-layer rotating pulping device, and water is added for forced stirring and pulping, so that the pulp reaches the fluidity, uniformity and other relevant technical requirements to adapt to the pressing section.

[0038] S4: placing the mixed slurry into a mold for pressing;

[0039] S41: putting the mixed slurry into a mold for pre-pressing;

[0040] Specifically, a positive high pressure (1200 tons pressure) and negative pressure adsorption rotation secondary pressing molding process is adopted. The uniformly prepared industrial waste gypsum mixed slurry is put into the mold and pre-pressed once to make the base surface flat.

[0041] S42 performs secondary pressing and molding on the material after the primary pre-pressing.

[0042] Specifically, the secondary facing fabric is subjected to secondary pressing and forming. During the pressing process, the water in the slurry can be squeezed out so that the blank can be quickly formed and demolded, and in the process of squeezing out the water, the solid matter in the mixed slurry is locked so that it does not flow away with the water, so as to retain the strength of the finished product. The finished product is dense and has few pores, so that the materials have a better bonding degree; at the same time, compared with the dry hardness, the water content control has a more relaxed ratio (15%-20%, dry hardness 6%-8%); at the same time, there is no vibration in the forming process, so the noise is small when the machine is working.

[0043] S5 demoulds and stores the pressed mixed slurry.

[0044] Specifically, specific pressing equipment is used to enable the product to be demoulded quickly, reduce mold occupancy, and improve mold use efficiency. Demolded products are tested online, and qualified products enter maintenance, polishing, storage, and re-testing before leaving the factory. Unqualified products enter the recycling cycle, and after re-treatment, they are used as raw materials for reproduction. For products with high decorative requirements, automatic water grinding is carried out to make them smoother and more beautiful for high-end gardens and road decoration. During the entire production pressing and polishing process, production wastewater containing solids will be generated. The wastewater will be collected and centralized separated and disposed. The separated solids will be added to the new pulping in a certain proportion and recycled; the separated water does not need to be purified and disposed, and can be directly used for pulping and polishing to achieve recycling. Therefore, the entire production process is a self-closed loop production, which does not produce secondary pollution emissions in the production process, and realizes the environmental protection requirements of industrial waste gypsum recycling production without re-pollution.

[0045] In a second aspect, a method for disposing of waste gypsum is used, which adopts the method for disposing of waste gypsum described in the first aspect and is applied to the treatment of waste gypsum to achieve recycling.

[0046] Beneficial effects:

[0047] 1. The present invention provides a method for treating waste gypsum. The main material is industrial waste gypsum. Physical excitation technology is used to improve the crystallization properties of gypsum to reduce the impact of various impurities in gypsum on the performance of gypsum by-products. At the same time, the excitation technology activates the potentially active slag in the industrial waste gypsum. High-density materials are prepared by combining high pressure with vacuum negative pressure. These materials are used to prepare building enclosure materials, gardens, and road materials.

[0048] 2. The present invention provides a method for the disposal of waste gypsum. The method uses industrial waste gypsum as the main raw material + auxiliary materials + special stimulants, and obtains high-density gypsum materials through a process combining high pressure and vacuum adsorption (or extrusion). Vacuum extrusion removes the gaps between the materials to increase the density and improve the various properties of the products: such as compression resistance, flexural strength and water resistance. The density of the obtained products (can reach 1.5 kg / cm3), while the density of other gypsum board products is generally 0.8-1.0 kg / cm3.

[0049] 3. The method for disposing waste gypsum provided by the present invention does not fry the industrial waste gypsum raw materials, does not generate secondary pollution, and can reduce costs. At the same time, the amount of industrial waste gypsum used is greater than 50%.

[0050] 4. The present invention provides a method for disposing of waste gypsum. The high-density industrial waste gypsum material obtained by the above process is used to produce high-quality pavement bricks, imitation slate bricks and imitation stone curbstones, which can be widely used in pavements, squares, gardens, residential areas, platforms and indoor and outdoor decoration, and can be used as an upgraded substitute for most of the original dry hard concrete block products, as well as an environmentally friendly alternative product for various types of stone finished products.

[0051] 5. The method for disposing of waste gypsum provided by the present invention is based on the technical requirements of garden and road products. In order to make the loose industrial waste gypsum form high density and high strength, the production mainly adopts a multi-station rotary full-wet stone-imitation filter press molding production process technology. Through the filter press technology combining positive pressure with vacuum water absorption, the product can have the high strength and density of terrazzo tiles, and has multiple properties such as strength, frost resistance, decoration and safety. The product can be polished by a later polishing machine to obtain an effect comparable to natural stone.

[0052] The above disclosure is only a preferred embodiment of a method for disposing of waste gypsum and its application of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention are still within the scope of the invention.

Claims

1. A method for disposing of waste gypsum, characterized in that: The following steps are involved: Pre-treating the waste gypsum to obtain a neutral water-containing material; The neutral water-containing material and the stimulant are weighed and prepared according to a preset ratio; Adding water to the prepared materials and stirring to obtain a mixed slurry; Putting the mixed slurry into a mold for pressing; The mixed slurry after pressing is demoulded and stored.

2. The method for disposing of waste gypsum according to claim 1, characterized in that: In "pre-treating waste gypsum to obtain neutral water-containing material", the pre-treatment includes mixing, stirring, comprehensive mixing of peracid and alkali, and molding.

3. The method for disposing of waste gypsum according to claim 1, characterized in that: In "the neutral water-containing material and the stimulant are weighed and prepared according to a preset ratio", the proportion of the neutral water-containing material is greater than 55%, and the proportion of the stimulant is less than 20%.

4. The method for disposing of waste gypsum according to claim 1, characterized in that: The step of "placing the mixed slurry into a mold for pressing" comprises the following steps: Put the mixed slurry into the mold for pre-pressing; The material after the primary pre-pressing is subjected to secondary pressing and molding.

5. A method for disposing waste gypsum, using the method for disposing waste gypsum according to any one of claims 1 to 4, characterized in that: Applied to waste gypsum treatment for recycling.

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