Low-temperature preparation method for lightweight heat-insulation ceramics

Abstract

The invention discloses a low-temperature preparation method for lightweight heat-insulation ceramics. Raw materials used in the preparation method comprise construction waste, ceramic polishing slag,fly ash, talc, feldspar, ball clay, diatomite and a foaming agent, wherein the amount of the solid waste is 60% or more. Pre-treated construction waste and other raw materials are subjected to ball milling mixing, and then subject to granulation, compaction molding, drying and low temperature sintering (700-1200 DEG C) to prepare the environmentally friendly lightweight heat-insulation ceramics.The method is simple in process, low in production cost and suitable for industrialized production. The prepared lightweight heat-insulation ceramics have the advantages of low density, controllable pore size, low heat conductivity, excellent mechanical properties and the like, and can be widely applied in heat preservation and heat insulation in the fields of architecture, chemical industry and the like. While achieving low temperature sintering, energy saving and emission reduction, the method can promote high-efficiency resource utilization of the solid waste, and is of great significance to the ecological environment.

Description

technical field [0001] The invention relates to a preparation method of light-weight heat-insulating ceramics, in particular to a low-temperature firing method of light-weight heat-insulating ceramics. Background technique [0002] Lightweight thermal insulation ceramics have small specific gravity and low thermal conductivity, and have been widely used in construction, energy, chemical industry, aerospace and other fields. In recent years, light-weight heat-insulating ceramics have been developed rapidly, but their preparation technology generally has disadvantages such as high raw material requirements, complex processes, high equipment requirements, and high firing temperatures. [0003] For example, the patent "a light-weight heat-insulating ceramic product and its manufacturing method" (CN105174905A), although the product has a unique negative ion release function and is used in the fields of health and environmental protection, the raw material requirements are high (e...

AI Technical Summary

Problems solved by technology

In recent years, light-weight heat-insulating ceramics have developed rapidly, but their preparation technology generally has shortcomings such as high raw material requirements, complicated processes, high equipment requirements, and high firing temperatures.

[0003] For example, the patent "a light-weight heat-insulating ceramic product and its manufacturing method" (CN105174905A), although the product has a unique negative ion release function and is used in the fields of health and environmental protection, the raw material requirements are high (especially containing rare earth oxides). Moreover, it needs to be pre-fired at 850-1000°C for 2.5-3.5h, and then heated to 1500-1650°C for 7-8h before it can be made. The firing temperature is high and it is difficult for ordinary ceramic kilns to achieve

The patent "a porous thermal insulation ceramic material for building and its preparation method" (CN106478077A) adopts the method of combining foaming technology and injection molding to prepare porous thermal insulation ceramics with uniform structure, good thermal insulation performance and thermal shock resistance, but Need to use reinforcing fiber, yttrium oxide or zirconia, etc., and the cost of raw materials is high

In addition, in a high-purity nitrogen atmosphere, quickly heat up to 1000-1200°C for 1-3 hours, then slowly heat up to 1300-1500°C, sinter for 1-2 hours, and then cool down to 600-1000°C for 1-5 hours after sintering. Produced with furnace cooling, high firing temperature, high energy consumption, strict requirements on kiln and other equipment, difficult to industrialize

The patent "A thermal insulation ceramic board and its preparation process" (CN104086205A) uses polishing waste, diatomaceous earth, foaming agent and other raw materials to make a thermal insulation ceramic board at 1100-1200 °C, but the raw material powder Need to pass 200-300 mesh sieve, high requirements for powder, and high firing temperature

The patent "a heat-insulating ceramic brick with low thermal conductivity and its preparation method" (CN103951397A) has prepared a heat-insulating ceramic brick with a thermal conductivity of less than 0.2 W / m·K, but the preparation process of the modified clay used is complicated and requires silicon Zirconium acid, zinc borate and other chemical raw materials have high raw material costs; when firing, they need to be kept at 820-860°C for 0.5-1h, then heated to 1220-1280°C for 1.5-2h, and then cooled to 740-780°C for 1- 1.5h, then raise the temperature to 1060-1120°C for 1-2h, and finally cool down to make it. The firing process is cumbersome, and the firing temperature is also high, which is not conducive to energy saving.

Patent "Low-temperature Environmental Protection Ceramics and Manufacturing Method" (CN105967644A), although the firing temperature is reduced to 900-950°C, achieving low-temperature firing, but the product is not lightweight ceramics

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