CN1394827A

CN1394827A - Method for calcining kaolin micropowder by using microwave electric field energy

Info

Publication number: CN1394827A
Application number: CN 01120156
Authority: CN
Inventors: 李勇
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-07-09
Filing date: 2001-07-09
Publication date: 2003-02-05

Abstract

The present invention discloses a process using microwave electric field energy to heat and calcine kaolin ultrafine powder material, and is characterized by that the kaolin ultrafine powder material is placed in a box (or tank) made of non-metal material, then said box is placed in an uniform microwave electric field, so that the microwave electric field energy can be passed through the interior of powder body in the box as light is passed through glass, the power body in the box can be simultaneously heated from interior to exterior so as to obtain the goal of calcining kaolin ultrafine powder material. Said invention adopts single electric energy, and can easily control calcining parameter and product quality.

Description

Method with microwave electric field energy calcined kaolin micro mist

The present invention relates to utilize microwave electric field energy heating means, specifically use the method for microwave electric field energy calcined kaolin micro mist.

In the past, it was along Gong Caiyong vertical furnace, tunnel furnace, the kiln of falling the cigarette or calcined by rotary kiln that countries in the world produce kaolinic calciner always, in order to guarantee product whiteness, mostly adopted the external-heat heating system.Production practice for several years proves this traditional external-heat tunnel furnace or calcined by rotary kiln processing unit repeatedly, contact inadequate transmission of heat by convection because of the indirect heat transfer of its high thermal resistance or because of gas-solid, be difficult to set up efficient flash heat transfer and control quality product effectively, so, cause that most part of kaolin manufacturer is absorbed in that industrial scale is little, investment is big, yields poorly, the energy consumption height, and quality product is difficult to the predicament of control stabilization.

In recent years, domestic constantly someone tests and adopts inflow attitude suspension calcining mode that kaolin is calcined, successively designed several dilute suspensions and be in the material powder is suspended in rising with single particle the hot gas flow and acutely exchanged, to improve heat exchange efficiency and calcinating speed with high temperature air stream.This design often also can be achieved success at the laboratory lab scale, but yet there are no applicable industries suspension calcining kiln so far in industrial production comes into operation, reason is with regard to present research and state of the art, also not on top of or control large scale industry suspension calcining kiln inner transmission matter, heat transfer, convection current, the width of cloth are penetrated, physical reaction, fluidization physics etc. are complicated factor and parameter, add the acquisition of a large amount of nearly 1000 ℃ high temperature airs and the difficult problems such as collection of-2 μ m ultra-fine micropowders and be in the way, make many producers drop into a large amount of manpower financial capacities and stranded.

Purpose of the present invention just provides the method for ethnic group with microwave electric field heating and calcining kaolin superfine powder, to improve rate of heating, shortens calcination time, optimization production environment, reaches the production effect of " getting twice the result with half the effort ".

To achieve these goals, the present invention adopts the HIGH-POWERED MICROWAVES process furnace to calcine the ultrafine kaolin powder, utilize microwave can be from the lining characteristics of outside diathermanous formula heating, the kaolin superfine powder is contained in is placed in the nonmetal box (case) among the uniform microwave electric field of the density that forms by microwave, allow microwave energy as the saturating powder inside of wearing of light penetration glass, whole box (case) powder is heated from inside to outside simultaneously, owing to the ultra high frequency of microwave in the microwave electric field is impelled material particle internal crystal framework water (hydroxy water) molecule and is produced frictional heat with the frequency vibration of microwave, so being rapidly heated, lattice hydroxyl moisture becomes steam, and form in inside high vapour pressure moisture content " is squeezed out " external, thereby realized taking off in the short period of time calcining purpose of hydroxy water.For homogeneous heating, when specifically making microwave oven, make the microwave that enters chamber more even be designed to two little inlets of symmetric arrangement from the nearer microwave entrance of antenna than small area, in chamber, form multiple interference region simultaneously, just can obtain the uniform microwave electric field of density.When powder magazine (case) by the time just can make the powder at each position in the magazine (case) obtain heating equably.In order to satisfy decarburization in the kaolin calcined process and to remove the needs of hydroxy water in the lattice, powder is in the control by low temperature, middle temperature, high-temperature zone and soaking time of the heating interval of microwave oven, to reach the incinerating purpose.

Use microwave electric field following advantage to be arranged the calcined kaolin ultrafine powder:

1, no matter how thick the bed of material is, the diathermanous calcining simultaneously of the inner core of powder material and skin, also heating evaporation and extruding fast from inside to outside of hydroxy water so shortened calcination time greatly, is enhanced productivity in its lattice.

2, container does not absorb heat, and useless heat dissipation is few in the kiln, and the microwave energy utilization ratio is high, produces power consumption and expense so save, to reduce production costs.

3, microwave calcination kaolin only uses the electric energy need not other energy, control reliability height, and operation is simple, free from environmental pollution and significantly reduced labour intensity, optimized production environment.

Claims

1, a kind of kaolin quick burning method with microwave electric field energy heating and calcining kaolin superfine powder, it is to be placed on by microwave and to form among the uniform microwave electric field of density being contained in kaolin superfine powder in the non-metallic container (case, box, tube etc.), allow the microwave electric field energy wear powder inside thoroughly, heat simultaneously from inside to outside and reach the calcining purpose.