Method for producing bodies of consolidated particulate material

A method for producing shaped bodies in which all surfaces are formed by an extruder by

• a) forming a flowable suspension of particulate material in a suitable liquid as an easily flowable moulding slurry wherein said liquid occupies interspaces between said particulate material,
• b) introducing said suspension into a complete moulding space with at least partly liquid-permeable walls,
• c) removing at least a major portion of said liquid by establishing a pressure differential across at least parts of said walls that are permeable to said liquid, so as in said complete moulding space to form a non-flowable, shaped body of said material, and
• d) removing said non-flowable, shaped body from said complete moulding space by reducing effects of friction in said complete moulding space,
• wherein step a) above includes homogenization of said suspension with a ratio between liquid and dry matter of 1:1 by weight, and
• wherein steps b) and c) above are carried out by pumping slurry into a closed extruder defining said complete moulding space and having a slurry inlet and finely perforated walls such that the method commences as a high-pressure slurry pumping process and terminates as a powder-pressing process and by applying a sufficiently high pressure to said slurry in said extruder to establish said pressure differential with a magnitude of 50-400 bar to consolidate said particulate material into said non-flowable, shaped body, whereby substantially all of said liquid in said interspaces is expelled from said complete moulding space such that said particulate material in said complete moulding space comes into close mutual engagement and said complete moulding space is occupied by closely packed and consolidated particulate material forming said non-flowable, shaped body having very low porosity, a uniform structure and considerable mechanical strength to thereby provide form stable bodies having sufficient mechanical strength to be handled immediately after leaving said extruder.