Preparation method of high-flux and high-precision ceramic ultrafiltration membrane for oil removal and iron removal of high-temperature condensed water

Abstract

The invention discloses a preparation method of a high-flux and high-precision ceramic ultrafiltration membrane for oil removal and iron removal of high-temperature condensed water. The method comprises the following steps: 1) preparation of a silicon-free porous alumina supporting body: 2) preparation of a transition layer membrane: and 3) preparation of a separation layer membrane. The prepared high-flux and high-precision ceramic ultrafiltration membrane for the high-temperature condensed water adopts the silicon-free system porous alumina supporting body, so in the process of using, no silicon is dissolved to cause secondary pollution of the condensed water after treatment; the prepared high-flux and high-precision ceramic ultrafiltration membrane for the high-temperature condensed water has high separation accuracy, the membrane average pore size is 5-50 nm, the membrane flux is high, the water yield is greater than 1.5 m<3> / m<2>*h, the oil content of the high-temperature condensed water after treatment is less than or equal to 0.3 mg / L, and the iron content of the high-temperature condensed water after treatment is less than or equal to 20 [mu]g / L; the bending strength is greater than 8000 N, and the membrane thermal stability is greater than 800 DEG C.

Description

technical field [0001] The invention relates to the field of preparation technology and application of porous ceramic membranes, in particular to a preparation method of a ceramic ultrafiltration membrane for removing oil and iron from high-temperature condensed water. Background technique [0002] At present, superheated steam is widely used as thermal power and heat source in chemical industry, thermal power and other industries. After power consumption and heat exchange, superheated steam turns into condensed water, and its temperature is between 50-99 degrees. If it is not polluted, steam condensed water It is close to pure distilled water, but due to pipe corrosion, material leakage, poor management and other reasons, the steam condensate water of most enterprises has certain pollutants such as oily substances, iron, etc., so it cannot directly enter the boiler for recycling, resulting in the large Most of the high-temperature condensate in most enterprises is dischar...

AI Technical Summary

Problems solved by technology

④The operating period of the membrane is long, up to 6-12 months

At present, inorganic ceramic membranes generally use porous alumina of 95 or 99 porcelain as the carrier, which contains oxides such as silicon oxide. The carrier of the silicon system contained in it will dissolve during use in a high temperature system, which will affect the silicon content of the condensed water after treatment. , the iron [Fe or Fe(OH), Fe(OH) contained in the high-temperature condensed water is an insoluble substance with a particle size of 80-100nm. To meet the requirement of iron removal, the pore size of the ceramic membrane separation layer will be below 50 nanometers. The separation accuracy of the ceramic membrane separation layer in the actual application process is affected by the maximum pore size. Because the ceramic membrane obtained by the porous ceramic membrane preparation process has a wide pore size distribution, the pore shape is not uniform, and the pore size cannot be guaranteed to be completely consistent, so the existence of macropores It is difficult to guarantee the filtration accuracy of iron in high temperature condensate water

The film layer of 50nm and below needs to be coated 3-4 times, the process is complicated, the production cost is high, and the membrane flux of the separation layer is small, and the film layer is easy to crack during the firing process. Application in Iron Removal and Reuse