A cement composition for extrusion, which is produced by incorporating, into cement mortar, 3 to 15 weight % of crushed pulp fiber, 0.2 to 1 weight % of at least one member selected from an alkylcellulose and a hydroxyalkyl­alkyllcellulose, 2% water solution having 80,000 cps or more viscosity, enables to cut production cost by reducing the loads of the binder material using a pulp fiber without carcinogenicitic asbestos fiber. Furthermore it allows to assure an excellent extrudability and to provide the moldings with such workability as nailing and sawing.

A first non-asbestos inorganic hardened composition comprising a mixture of 100 parts by weight of cement, 5 to 60 parts by weight of quartzite powder, 5 to 60 parts by weight of wollastonite, and 0.1 to 10 parts by weight of fiber, mixed with an appropriate amount of water, molded, and hardened, and a second non-asbestos inorganic hardened composition based on the first composition, further comprising: (A) 0.2 to 8 parts by weight of an alkali metal chloride or an alkaline earth metal chloride, and/or (B) 0.1 to 6 parts by weight of a water reducing agent and 0.1 to 4 parts by weight of a thickener; and a method for producing a non-asbestos inorganic hardened composition comprising adding an appropriate amount of water to the above composition, and subjecting the mixture to an extrusion process, a roll pressing process, and a flat pressing process followed by hardening and curing.

Reinforcing fibres made from polyolefin and polyolefin derivatives, the fibres having a thickness of 10-100 µm and containing inorganic particles of a size of 1-10 µm in an amount of at least 12% by weight, calculated on the total fibre weight, the particles being embedded in the polyolefin or polyolefin derivative, substantially none of the particles being exposed at fibre surfaces. The inorganic particles are preferably chalk or barium sulphate. The fibres are prepared from a fibrillated, stretched, blown or cast film, which may have been subjected to a surface treatment such as a corona treatment or application of avivage. The reinforcing fibers are useful in com­posite materials comprising an inorganic binder such as cement and puzzolane.

A calcium silicate filler mass for use in storing a gas solution or liquid gas, said filler mass having a high compressive strength and containing at least 0.5 weight percent reinforcing carbon fibers uniformly disposed within said calcium silicate (11), said filler having uniformly distributed throughout very fine pores of less than about 25 microns, and being substantially absent of voids and having a porosity of at least about 85%. There is also disclosed an acetylene storage vessel for storing gas solutions of acetylene which includes said silicate filler mass (11) disposed within a metal shell (10) and a method of forming said acetylene storage vessel.

In a process for the manufacture of green shaped articles having a density of at least 1000 kg/m³ and a matrix of a cured inorganic binder said articles are prepared by dewatering an aqueous slurry of fibres and a matrix forming material comprising particles of an inorganic hydraulic binder, particulate inorganic additive and possibly other additives containing an excess of water in relation to the amount necessary to secure curing of the hydraulic binder, and containing, on a dry weight basis, 3-20%, preferably 5-20%, in particular 7-15%, cellulose fibres, after which the green shaped articles are cured. The matrix forming material comprises, on a dry weight basis,



40-90%, preferably 45-85%, of a coarse material with an average particle size of 35-12 µm, preferably 25-18 µm, preferably with a particle size distribution exhibiting only one maximum, comprising the hydraulic binder and possibly a silica- or silicate-containing, preferably pozzolanic active additive,



5-45%, preferably 10-40%, in particular 10-35%, of a fine inorganic, preferably silica- or silicate-containing, in particular pozzolanic active additiv e with an average particle size of 10-1 µm, preferably 7-3 µm, preferably with a particle size distribution cxhibiting only one maximum,



3-25% of an ultra fine preferably pozzolanic active additive with an average particle size within the range 1-0.02 µm, preferably less than 0.5 µm, and



0-30% other additives.

There is provided a shaped three-dimensional calcined phosphate-bonded magnesium silicate comprising the shaped reaction product of phosphoric acid with a natural magnesium silicate selected from uncalcined magnesium silicate and magnesium silicate tailings which have been calcined at a temperature of from 800 to 1300°C, provided that the reaction product of phosphoric acid with uncalcined magnesium silicate has been calcined at a temperature of from 800 to 1100°C while shaping, the selected magnesium silicate having an aspect ratio ^t_d⋞ 500 wherein f is the average length and d is the average diameter of the selected natural magnesium silicate particle. The products are useful as insulating products, firewall and casting products and dielectric products depending on the amount of each starting material used and are furhter characterized by being asbestos-free.

A fiber reinforced heat resistant asbestos free article such as a board, its method of manufacture and the composition used in its manufacture. The board comprises less than 10 weight percent water and the balance being solids which comprise from about 1 to about 6 weight percent organic fibres, from about 15 to about 40 weight percent ceramic fibers, from about 1 to about 6 weight percent organic binder, 0 to about 5 weight percent colloidal silica, from about 0.2 to about 2 weight percent of a flocculent, and from about 50 to about 80 weight percent inorganic high temperature filler. The composition used in the manufacture of the board comprises the components of the above article dispersed in water. The method comprises draining water from the composition and drying the resulting article.