Magnesium aluminate spinel reinforced magnesium oxide-based foam ceramic filter synthesized in situ from magnesium oxide whisker, and preparation method therefor

A method for preparing a magnesium oxide whisker in-situ formed MA spinel-reinforced magnesium oxide-based ceramic foam filter wherein the method comprises the steps of:

• 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising a magnesium oxide whiskers, and then adding deionized water and ball milling to mix until uniform, and vacuum degassing the mixture;
• the rheological agent is a mixture of a urea formaldehyde resin and a cellulose ether, wherein the urea formaldehyde resin accounts for 20% of the mass of the rheological agent, the cellulose ether is one of industrial-use hydroxyethyl cellulose and hydroxy propyl methyl cellulose, or a mixture thereof;
• the magnesium oxide ceramic powder comprising magnesium oxide whiskers is a mixture of a fused magnesium oxide powder and a magnesium oxide whisker powder;
• 2) soaking a polyurethane foam template into the ceramic slurry, squeezing by a roller press the polyurethane foam template to remove redundant slurry to make a biscuit, and drying the biscuit by heating it to 80°-120° C.;
• 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1400° C.-1600° C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.