A lightweight micro-closed-pore corundum composite refractory and a method preparing the same, wherein raw materials of the refractory comprise 95-99 parts by weight of -Al.sub.2O.sub.3 micro-powder and 1-5 parts by weight of dolomite clinker; and additives of the refractory comprise 2-15 parts by weight of nano alumina sol, 5-15 parts by weight of a carbohydrate polymer, and 30-50 parts by weight of an organic alcohol. and the lightweight micro-closed-pore corundum composite refractory is prepared by: mixing and wet grinding the raw materials and the additives to obtain a slurry; placing the slurry in a mold, keeping the mold at 15-25 C. for 6-12 hours and then keeping the mold at 60-90 C. for 6-12 hours, then demolding; drying a demolded green body at 110-200 C. for 24-36 hours, and keeping the green body at 1800-2000 C. for 2-5 hours. A method preparing a lightweight micro-closed-pore corundum composite refractory is also provided. The lightweight micro-closed-pore corundum composite refractory of the present invention has characteristics of low bulk density, small average pore size, high closed porosity, low thermal conductivity, strong thermal shock resistance, abrasion resistance and slag resistance.

Systems and methods for preparing a three-dimensional printing material derived from aluminosilicate material are provided. The method includes the steps of heating an amount of aluminosilicate powder to a temperature between approximately 1,100? C. and approximately 1,750? C. to form a molten aluminosilicate material; maintaining the molten aluminosilicate material at a temperature between approximately 1,100? C. and approximately 1,750? C. between about one minute and approximately 45 minutes; extruding molten aluminosilicate material through a nozzle to form an elongated bead of molten aluminosilicate material; and cooling the molten aluminosilicate material to form a hardened aluminosilicate material. Once hardened, the aluminosilicate material includes between about 50% and 90% feldspar and demonstrates a strength of between about 5,000 psi and 30,000 psi. The systems and methods enable the construction of structures using raw, in-situ natural resources without the need for additives to adjust or modify the viscosity of the molten material prior to extrusion or printing.

A first circumferential wall disposed in a circumference of partition walls has no interface with the outermost circumference partition wall in a circumferential portion constituted by the partition walls whose wall thickness is larger than that of a central portion constituted by the partition walls in a central region. A maximum thickness of a total of the first circumferential wall and a second circumferential wall disposed to surround an outer side of the first circumferential wall is 1.2-3.0 mm, a difference between the maximum thickness and a minimum thickness of the total is 0.2-1.5 mm, and there is satisfied a relation, 0.5(TBTA)SB/SA100(%)9.0 in which TB and TA indicate average thicknesses (m) of the partition walls in the circumferential and central portion respectively, and SB and SA indicate areas (cm.sup.2) of the circumferential portion and the honeycomb structure in the cross section respectively.

A nozzle sand and method of use and operation, utilizes as a constituent component a granulated material that will break down to lose structural integrity and strength when subjected to temperatures and weight of molten ferrous materials, to compact to form at least a partial barrier to penetration of the molten ferrous material while remaining at least substantially in a granulated state. When the nozzle is opened, the loose nozzle sand will freely flow from the nozzle and the barrier will break under the weight of the ferrous material, such that the ferrous material will flow from the vessel through the nozzle. As a representative formulation, the nozzle sand can include between about 50 percent and about 60 percent by weight raw dolomitic lime; between about 20 percent and about 30 percent by weight forsterite; and between about 15 percent and about 20 percent by weight tabular alumina.

A method for producing granulates, particularly for use as thermal insulation for a metal melt may include mixing a powdery mineral with a binder, and the mixture may be granulated in order to produce a semi-finished product. The granulate mixture or the semi-finished product may be heated rapidly to a temperature above the melting temperature or decomposition temperature of the binder, which may be in the form of a salt, so that the binder decomposes, whereby gas is released and the volume increases. The apparent density of the granulate mixture may decrease, and therefore the apparent density of the finished product may decrease with respect to the semi-finished product.

A proppant for use in fracturing geological formations is made from bauxitic ores and a calcium containing compound. The proppant has a calcium containing crystalline phase.

The invention relates to a refractory ceramic batch for the production of an unformed refractory ceramic batch, the use of a batch of this kind for lining metallurgical melting vessels and also a metallurgical melting vessel which is lined with an unformed refractory ceramic product based on a batch of this kind.

Glazed ceramic material with a low coefficient of thermal expansion to be used as the main raw material (65% to 85%) in porcelain stoneware compositions to manufacture large format sheets (larger than 1.4 m) and also to be used as the main raw material in the manufacture of a glaze (85% to 95%) that will provide the large format sheet with a waterproof, protective and decorative surface. The frit will give the set (body with glaze) a very low coefficient of thermal expansion (hereinafter referred to as CTE). In addition, the resulting ceramic composition can be processed in a conventional ceramics kiln, as aspects such as melt viscosity or adhesion to the rollers have been taken into account during development. As it has a very low CTE, glazed ceramic material can be used as a substitute for glass ceramic material used in the manufacture of induction hobs. This glazed ceramic material can be coloured (both the body and the glaze) and decorated (the glaze), thus adding a new feature to the traditional induction hob.

An anode for a direct current electric arc furnace includes dry vibratable monolithic refractory material positioned on a bottom wall of the furnace, a plurality of steel pins extending upward from the bottom wall of the furnace and through the dry vibratable monolithic refractory material, and an anode cap positioned on top of the dry vibratable monolithic refractory material. The steel pins are surrounded by the dry vibratable monolithic refractory material. The anode cap includes a plurality of pin holes formed therein with which the steel pins correspond and through which the steel pins extend.