CN111960788A - Process method and process equipment for preparing plastering gypsum from iron tailings - Google Patents

Process method and process equipment for preparing plastering gypsum from iron tailings Download PDF

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Publication number
CN111960788A
CN111960788A CN202010777640.9A CN202010777640A CN111960788A CN 111960788 A CN111960788 A CN 111960788A CN 202010777640 A CN202010777640 A CN 202010777640A CN 111960788 A CN111960788 A CN 111960788A
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Prior art keywords
iron tailings
gypsum
plastering gypsum
preparing
tailings
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CN202010777640.9A
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刘兴兵
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刘兴兵
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Priority to CN202010777640.9A priority Critical patent/CN111960788A/en
Publication of CN111960788A publication Critical patent/CN111960788A/en
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    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/14Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing calcium sulfate cements
    • C04B28/142Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing calcium sulfate cements containing synthetic or waste calcium sulfate cements
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B11/00Calcium sulfate cements
    • C04B11/02Methods and apparatus for dehydrating gypsum
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B11/00Calcium sulfate cements
    • C04B11/26Calcium sulfate cements strating from chemical gypsum; starting from phosphogypsum or from waste, e.g. purification products of smoke

Abstract

The invention discloses a process method and process equipment for preparing plastering gypsum from iron tailings, wherein the process method comprises the following steps: dehydrating and calcining the iron tailings suitable for preparing plastering gypsum; grinding the calcined and cooled iron tailings; and mixing the active material, the composite exciting agent, the chemical exciting agent and the lightweight aggregate with the milled iron tailings to obtain a gypsum-like gel material, namely plastering gypsum. The plastering gypsum project comprehensively utilizes the mine tailings, reduces the land used for stockpiling the tailings, has great significance in the aspects of safety, environmental protection, saving intensive land and the like, and the developed product is a novel wall plastering material popular in the building material market and can replace high-energy-consumption cement.

Description

Process method and process equipment for preparing plastering gypsum from iron tailings
Technical Field
The invention relates to a process method and process equipment for preparing plastering gypsum from iron tailings.
Background
The iron tailings are wastes after mineral separation and are the main components of industrial solid wastes.
The quantity of iron tailings stockpiled in China is up to billions of tons, and accounts for nearly 1/3 of the total stockpiled quantity of all tailings. Therefore, the comprehensive recycling problem of the iron tailings has received extensive attention of the whole society.
The mae-steelo river mining industry is engaged in the iron ore mining industry, the filling method mining and the flotation and magnetic separation production process flow are adopted, and the surplus tailings after full tailing filling are about 40% (60-90 ten thousand t/a). The mineral phase composition of the mine tailings has the characteristics of low silicon-aluminum content and higher gypsum content, wherein particles with the particle size of less than 0.15mm account for more than 50 percent, and are not suitable to be used as aggregate in building materials.
In the process of implementing the comprehensive recycling of the roxburgh iron tailings, the inventor finds that: the Luo river iron tailings do not contain radioactivity and leaching toxicity, and after modification and activation hydration by adding auxiliary materials, the binding components such as gypsum, meta-aluminate, meta-silicate and the like in the iron tailings can be effectively utilized to produce novel building material products similar to interior wall plastering gypsum.
The plastering gypsum is an air-setting cementing material prepared by taking building gypsum as a main component and doping various additives and aggregates, is a plastering material for the surfaces of building interior walls and top plates, and is a replacement product of traditional cement mortar or mixed mortar. The building gypsum has the advantages of fast hardening, early strength, strong cohesive force, good volume stability, moisture absorption, fire resistance, light weight and the like, and overcomes the defects of over-fast setting speed, large viscosity, inconvenient plastering operation and the like of the building gypsum.
Plastering gypsum mortar is a widely used building plastering product abroad, and in Europe, gypsum mortar accounts for more than 70 percent of the total amount of plastering mortar. The research and development of plastering gypsum in China are relatively late, and the research on plastering gypsum is not carried out until related scientific research institutes in the early 80 s of the 20 th century.
The gypsum industry in China has been developed rapidly in recent 40 years, and as for the plastering gypsum, the technology level, the product variety and the product quality are greatly improved, the production scale and the equipment level are also greatly improved, and the application range of the plastering gypsum is gradually expanded.
Disclosure of Invention
The invention aims to provide a process method and process equipment for preparing plastering gypsum from iron tailings, so as to perform harmless treatment on the iron tailings and change waste into valuable.
Therefore, the invention provides a process method for preparing plastering gypsum from iron tailings, which comprises the following steps: dehydrating and calcining the iron tailings suitable for preparing plastering gypsum; grinding the calcined and cooled iron tailings; and mixing the active material, the composite exciting agent, the chemical exciting agent and the lightweight aggregate with the milled iron tailings to obtain a gypsum-like gel material, namely plastering gypsum.
According to another aspect of the invention, there is provided a process equipment for preparing plastering gypsum from iron tailings, comprising: the iron tailing process equipment is used for calcining and grinding iron tailings and comprises a wet raw material buffer bin, a direct flame roasting kiln, a cooling machine, a raw material buffer bin, a dry ball mill and a dry tailing homogenizing bin which are sequentially arranged according to a process route; the light aggregate process equipment is used for processing perlite mineral powder into perlite expanded particles and comprises a preheating furnace, an expansion furnace and a reticular storage bin which are sequentially arranged according to a process route; the device comprises an active material bin for storing an active material, a compound excitant bin for storing a compound excitant and a chemical excitant bin for storing a chemical excitant; and the gravity-free mixer is used for mixing the weighed ground iron tailings, the perlite expanded particles, the chemical excitant, the active material and the composite excitant to obtain a gypsum-like gel material, namely the plastering gypsum.
The method for producing the plastering gypsum by using the iron tailings accords with the principles of comprehensive utilization and harmless treatment of waste resources and industrial waste residues encouraged by China, has higher economic benefit, environmental benefit and social benefit, is beneficial to environmental protection of China, accords with the strategy of sustainable development, and has very important significance for saving resources and improving the environment.
The plastering gypsum project comprehensively utilizes the mine tailings, reduces the storage land of the tailings, has important significance in safety, environmental protection, saving intensive land and the like, and the developed product is a novel wall plastering material popular in the building material market and can replace high-energy-consumption cement.
In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a flow chart of a process for preparing plastering gypsum from iron tailings according to the invention;
fig. 2 is a process route diagram of a process assembly for preparing plastering gypsum from iron tailings according to the present invention.
Detailed Description
The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
Fig. 1 is a flow chart of a process method for preparing plastering gypsum from iron tailings according to the invention. The steps of the process route for preparing plastering gypsum from iron tailings of the present invention are described in detail with reference to fig. 1.
S1, firstly sampling, judging whether the iron tailings are suitable for preparing plastering gypsum according to sampling analysis, if so, selecting the iron tailings as a raw material for preparing plastering gypsum, otherwise, giving up.
The iron tailings judging conditions are as follows: the iron tailings do not contain radioactivity and leaching toxicity, and after modification and activation hydration by adding auxiliary materials, the gelation components such as gypsum, meta-aluminate, metasilicate and the like in the iron tailings can be effectively utilized to produce novel building material products similar to interior wall plastering gypsum plaster.
Examples of such applications are
The iron tailing sample is from Roghe iron ore, the Roghe iron ore is located in 30 Km of Dongfeng village in Roghe town of Lujiang county of Anhui province, and the total area of the ore area is 4.4Km2The ascertained storage capacity of the iron ore reaches 5 hundred million tons, the storage capacity approved by the national storage commission is 3.4 hundred million tons, and the grade is 35.82%. During production, a large amount of tailings is produced.
The iron tailing sample is obtained from a production line by lughe iron ore, the sample is water-containing slurry, and the sample amount is 1 barrel of a plastic barrel with 50 kg. Drying the sample in a drying oven, manually crushing the agglomerates, fully mixing, and taking out a certain amount of sample for analysis respectively. From the viewpoint of the application of the construction material, the composition of the sample, the grain composition, the state of aggregation of elements, the hardness of particles, the compatibility between particles and cement, the radioactivity of the sample, and the like are mainly analyzed.
From the component analysis, the main elements in the sample are iron, calcium, silicon and sulfur; the secondary elements are aluminum, magnesium, phosphorus and potassium. From the phase composition, the sample consists essentially of a medium phase: CaSO4, SiO2, CaSO4 & 0.5H2O, FeS2, while zeolite, Fe2O3, Al2O3, Al2(SO4)3, pyroxene, diopside are less in content.
Different from other literature reports on iron tailings, the content of silicon oxide and aluminum oxide is low, and the content of gypsum is high. This may have a great relationship with the sample source, and according to the literature data on geological exploration and identification of lughe iron ore, the ore belongs to a mineral deposit formed by symbiosis of large iron ore, pyrite and anhydrite, and the ore belongs to magnetite, so that more gypsum is related to the factor in the sample.
The content of anhydrite (CaSO4) and hemihydrate gypsum (CaSO 4.0.5H 2O) in the phase composition is higher (more than 60 percent), and the method is related to sample drying in the experimental process.
From the aspect of particle size distribution, the sample mainly contains fine particles, wherein the particles with the particle size of less than 0.15mm account for more than 50 percent, and the sample is not suitable for being used as aggregate in building materials.
The firmness of the samples was measured by the crush index method, which reflects the lower hardness of the samples.
The results of the radioactivity evaluation of the samples show that the samples are safe for use in the production of building materials or building products. The sample has better compatibility with cement.
Comprehensive judgment shows that the roxburgh iron tailings are suitable for preparing plastering gypsum.
And S2, filtering and dehydrating the iron tailings.
Taking the roxburgh iron tailings as an example, the water content of the iron tailings dehydrated by the ceramic filter is about 10.5%.
And S3, calcining the iron tailings.
Preferably, the calcining temperature is 700 ℃ and the calcining time is 20min-30 min.
Optional calcination equipment: a box-pot continuous kiln (such as a tunnel kiln, a roller kiln and the like), an indirect heating rotary kiln and an internal heating rotary kiln. Preferably an internal heat rotary kiln.
Because the temperature of the roasted material is high, the roasted material cannot enter a ball mill for grinding, and the roasted material needs to be cooled, for example, a single-cylinder spray cooling machine is selected for cooling, the material is cooled to about 60 ℃, and then the next procedure is carried out.
And S4, grinding the iron tailings.
The tailings are ground by using a powder making device, particles are controlled to be distributed in a relatively narrow range (200 meshes), and the surface roughness and the internal microcracks of the particles are increased, so that the surface activity of the tailings is enhanced; and the dissolving activity of gypsum in tailings is improved by combining a calcination process.
And (3) performing a bond work index experiment on the material, and performing equipment type selection according to the bond work index experiment result of the tailings, wherein preferably, the ore grinding equipment is a dry-type ball mill.
And S5, mixing materials.
The doping objects are divided into: active materials, composite activators and chemical activators. Among these, it is important to incorporate active materials, such as slag, cement clinker, etc., to increase the strength of the gel mass, overcoming the problem of insufficient strength of the gel mass. And mixing a composite excitant and a trace amount of chemical excitant to excite the gypsum gel material. The mixing device is preferably a gravity-free mixer to obtain the gypsum-like gel material.
In one embodiment, the composite activator is desulfurized gypsum and the chemical activator is a strong base. These materials are available from outsources. The mass percent of each material is as follows: 20.23% of active material, 5% of composite excitant, 0.0015% of chemical excitant, 4.77% of lightweight aggregate (perlite) and the balance of iron tailings (about 70%).
The gel material is converted into various calcium silicates in the hydration process of aluminosilicate and calcium sulfate after wet mixing, such as: 0.9nm tobermorite (Ca)5Si6O18H2) 1.1nm tobermorite (Ca)5Si6O17·5H2O) and 1.4nm tobermorite (Ca)5Si6O18H2·8H2O), quartz, beryl, anhydrite and calcite.
The cementitious material has the air hardening characteristics of gypsum cementitious materials, but its gelling mechanism is shifted to anhydrite and calcium silicate as the main gelling.
S6, mixing the lightweight aggregate.
Mixing with lightweight aggregate such as expanded perlite particles to obtain lightweight plastering gypsum.
The mortar material prepared by the mortar material completely meets the relevant requirements of plastering gypsum national standard GB/T28627 and 2012 plastering gypsum. The physical properties of the mortar are greatly superior to those of mortar prepared from desulfurized hemihydrate gypsum and phosphogypsum hemihydrate gypsum.
In one embodiment, the lightweight aggregate (perlite) is blended and mixed with the active material, the composite activator and the chemical activator at the same time to form the lightweight plastering gypsum product.
The process equipment for preparing plastering gypsum from the iron tailings is described by taking the treatment of the roxburgh iron tailings as an example in combination with the figure 2.
The luohe iron tailings are fed by a belt conveyor in a tailings filter pressing workshop of an iron ore dressing plant.
The iron tailings (with the water content of about 10.5%) after filtration and dehydration are conveyed to 200m by a 370m sealed belt conveyor (DT 2A-B800X 400)3The wet raw material is delivered to a direct flame roasting kiln (NR3348) for roasting through a vibrating feeder (GZD-650 x 2300) and a feeding conveyor (LR-DEL800-3000) in a wet raw material buffer bin (phi 6 x 8m steel tank).
After the roasted material is fed into a cooler (phi 3 x 30m) through a chute for cooling, the cooled material passes through an air conveying bin pump (Q is 35t/H, L is 15m, H is 5m, and rho is 1.6 t/m)3) 100m before feeding into mill3And (4) caching the dry raw material in a buffer bin (phi 6 multiplied by 3.5m steel tank).
Feeding the materials in a buffering bin before grinding into a dry ball mill (phi 2400 multiplied by 8000) through a vibration hopper (FY-2000ZDD) and a belt scale (LR-DEL800-3000) to grind, and conveying the materials after grinding into a pneumatic conveying bin pump (Q is 35t/H, L is 20m, H is 20m, and rho is 1.6 t/m)3) Feeding into 3 dry tailings homogenizing silos (phi 8X 20m steel tank, 1000 m)3)。
The outsourcing bulk active material is directly fed into 2 containers of 150m by a canned automobile3Active material silo (phi 6 x 6m steel tank). The outsourcing composite excitant is directly fed into 2 150m canned automobiles3Compound excitant storehouse (phi 6 x 6m steel can). Outsourcing chemical excitant is fed into 2 chemical excitant bins (phi 4 x 2m steel tank, 25m3) from a ton bag small bag dumping station through a vibration hopper (FY-1500 ZDD).
The purchased perlite raw mineral powder is fed into a material pouring station of a ton bag small bag, is fed into a preheating furnace through a belt conveyor to be preheated, the preheated perlite is fed into an expansion furnace through a pneumatic conveying bin pump, the expanded perlite is fed into a reticular storage bin through a primary feeding fan to be cooled and cached, and then is directly fed into a proportioning bin of a gravity-free mixer through a secondary feeding fan.
The roasted tailings, active materials, composite excitant, chemical excitant, light aggregate (expanded perlite) and other raw materials are transferred in a blending bin of a pneumatic conveying mixer and are respectively fed into a gravity-free mixer (6 m) through a metering screw conveyor3) After mixing for a period of time, the mixture is fed into a finished product buffer bin through a chute, packaged by a pneumatic packaging machine, stacked by a robot and transferred to a bagged finished product warehouse. The bulk finished products are directly loaded in a finished product buffer bin.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A process method for preparing plastering gypsum from iron tailings is characterized by comprising the following steps:
dehydrating and calcining the iron tailings suitable for preparing plastering gypsum;
grinding the calcined and cooled iron tailings; and
mixing the active material, the composite excitant, the chemical excitant, the lightweight aggregate and the ground iron tailings to obtain a gypsum-like gel material, namely plastering gypsum.
2. The process method for preparing plastering gypsum from iron tailings according to claim 1, further comprising:
and judging whether the iron tailings are suitable for preparing plastering gypsum according to sampling analysis, and if the iron tailings are suitable for preparing the plastering gypsum, selecting the iron tailings as a preparation raw material of the plastering gypsum.
3. The process for preparing plastering gypsum from iron tailings according to claim 1, wherein the iron tailings are luo he iron tailings.
4. The process method for preparing plastering gypsum from iron tailings according to claim 1, wherein the calcination temperature is 650-750 ℃ and the calcination time is 20-30 min.
5. The process for preparing plastering gypsum from the iron tailings according to claim 1, wherein the iron tailings after calcination and cooling are ground to 200 meshes.
6. The process for preparing plastering gypsum from iron tailings according to claim 1, wherein the active material is used for increasing the strength of the setting compound.
7. The technical equipment for preparing plastering gypsum from iron tailings is characterized by comprising the following steps:
the iron tailing process equipment is used for calcining and grinding iron tailings and comprises a wet raw material buffer bin, a direct flame roasting kiln, a cooling machine, a raw material buffer bin, a dry ball mill and a dry tailing homogenizing bin which are sequentially arranged according to a process route; the light aggregate process equipment is used for processing perlite mineral powder into perlite expanded particles and comprises a preheating furnace, an expansion furnace and a reticular storage bin which are sequentially arranged according to a process route;
the device comprises an active material bin for storing an active material, a compound excitant bin for storing a compound excitant and a chemical excitant bin for storing a chemical excitant;
and the gravity-free mixer is used for mixing the weighed ground iron tailings, the perlite expanded particles, the chemical excitant, the active material and the composite excitant to obtain a gypsum-like setting adhesive material, namely plastering gypsum.
CN202010777640.9A 2020-08-05 2020-08-05 Process method and process equipment for preparing plastering gypsum from iron tailings Pending CN111960788A (en)

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CN202010777640.9A CN111960788A (en) 2020-08-05 2020-08-05 Process method and process equipment for preparing plastering gypsum from iron tailings

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101560083A (en) * 2009-06-02 2009-10-21 河北科技大学 Dry powder mortar of mine tailings
CN102531512A (en) * 2011-12-27 2012-07-04 长安大学 Plastering material prepared by iron tailings or quartzitic coal gangue and desulfurized gypsum
CN102603358A (en) * 2012-03-26 2012-07-25 遵化市海祥新型建材有限责任公司 Production method for iron tailing sand aerated concrete building block
CN105753421A (en) * 2016-01-29 2016-07-13 安徽省皖北煤电集团有限责任公司含山恒泰非金属材料分公司 Natural anhydrite based lightweight interior wall plastering gypsum material and preparation method thereof
CN109987912A (en) * 2019-03-10 2019-07-09 胡春宇 Zeolite prepares iron tailings dry powder and mortar

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101560083A (en) * 2009-06-02 2009-10-21 河北科技大学 Dry powder mortar of mine tailings
CN102531512A (en) * 2011-12-27 2012-07-04 长安大学 Plastering material prepared by iron tailings or quartzitic coal gangue and desulfurized gypsum
CN102603358A (en) * 2012-03-26 2012-07-25 遵化市海祥新型建材有限责任公司 Production method for iron tailing sand aerated concrete building block
CN105753421A (en) * 2016-01-29 2016-07-13 安徽省皖北煤电集团有限责任公司含山恒泰非金属材料分公司 Natural anhydrite based lightweight interior wall plastering gypsum material and preparation method thereof
CN109987912A (en) * 2019-03-10 2019-07-09 胡春宇 Zeolite prepares iron tailings dry powder and mortar

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