The present invention relates to an arrangement for low-pressure casting of refractory metals, with a furnace chamber with one or a plurality of gas supply openings (6) and gas outlet openings (7), and a riser pipe (8) through a cover (5) of the furnace chamber, a melting container (3, 12) for the refractory metals arranged in the furnace chamber, and a heating device for heating the refractory metals in the melting container (3, 12). In the proposed arrangement, the melting container (3, 12) is formed as an exchangeable insert for a receiving mould (2) supporting the melting container (3, 12), which is arranged in the furnace chamber, wherein a thermally insulating layer (4, 17) is formed between the receiving mould (2) and the melting container (3, 12), or is integrated into the melting container (3, 12). With the proposed arrangement, a quick and easy exchange of the melting container for different alloys can also be carried out in the low-pressure casting of refractory metals.

A cold crucible usable in the field of high-temperature production of monocrystalline materials. The cold crucible includes: a cold cage which has sectors made of a material having good electrical conductivity and in which a charge is melted, and a cooling device with heat transfer fluid, configured to cool each segment of the cold cage from the inside. The cold crucible is essentially such that it further includes at least one device for generating a static magnetic field, each generating device being housed inside one of the sectors of the cold crucible. Each static magnetic field thus generated having the effect of slowing down the electromagnetic stirring of the molten charge, such that it is possible to produce monocrystalline ingots of significantly larger diameter than the diameter of the seed initiating their growth.

A cold crucible having application in the field of making monocrystalline materials at high temperature. The cold crucible includes: a cold cage having sectors made of a good electrical conductor material and in which a charge is molten, and a cooling device with a heat-transfer fluid, configured so as to cool down, from inside, each segment of the cold cage. At least one sector of the cold crucible includes a housing and is removable, the housing being proper and intended to accommodate at least one so-called functionalising device of the cold crucible. Henceforth, it is possible to functionalise each sector independently of the others, by accommodating therein, a functionalising device configured, inter alia, so as to modify and/or analyse at least one property of the charge, in particular the molten charge, in the cold cage.

The present invention relates to an arrangement for low-pressure casting of refractory metals, with a furnace chamber with one or a plurality of gas supply openings (6) and gas outlet openings (7), and a riser pipe (8) through a cover (5) of the furnace chamber, a melting container (3, 12) for the refractory metals arranged in the furnace chamber, and a heating device for heating the refractory metals in the melting container (3, 12). In the proposed arrangement, the melting container (3, 12) is formed as an exchangeable insert for a receiving mould (2) supporting the melting container (3, 12), which is arranged in the furnace chamber, wherein a thermally insulating layer (4, 17) is formed between the receiving mould (2) and the melting container (3, 12), or is integrated into the melting container (3, 12). With the proposed arrangement, a quick and easy exchange of the melting container for different alloys can also be carried out in the low-pressure casting of refractory metals.

A metal oxide barrier and a connecting method for solving the problems in which sectors of an existing cold crucible are connected by means of a mica plate and the mica plate is damaged due to arcing and the like and in which the sectors are strongly connected by means of the mica plate and thus are difficult to replace and maintain. A cold crucible, comprising a metal oxide barrier, according to the present invention can prevent arcing, enables reduction of damage on the edge part of a water cooling sector due to a molten material and thus enhances durability. Moreover, the metal oxide barrier can easily be replaced compared to an existing mica plate and thus enables easy maintenance and repair.

A cold crucible structure according to an embodiment of the present invention includes a cold crucible structure according to an embodiment of the present invention includes: a cold crucible unit including hollow top and bottom caps, a plurality of segments connecting the top cap and the bottom cap, slits disposed between the segments, and a reaction area surrounded by the segments; and an induction coil unit disposed to cover the outer side of the cold crucible unit and disposed across the longitudinal directions of the segments and the slits, in which the diameter of the reaction area is defined as a crucible diameter, the crucible diameter is 100 to 300 mm, and a width of each of the slits is defined by $d_{\mathrm{slit}}\le 0.3\times \frac{\varnothing }{50}$
(mm)(where d.sub.slit is the width of each of the slits and Ø is the crucible diameter).

An electric induction system and method is provided for induction heating and melting of basalt charge for the production of molten process basalt that can be used for molten basalt processes that produce basalt articles of manufacture including cast basalt articles and continuous basalt casting processes for producing basalt articles such as fibers and filaments.

A cold crucible structure according to an embodiment of the present invention includes a cold crucible structure according to an embodiment of the present invention includes: a cold crucible unit including hollow top and bottom caps, a plurality of segments connecting the top cap and the bottom cap, slits disposed between the segments, and a reaction area surrounded by the segments; and an induction coil unit disposed to cover the outer side of the cold crucible unit and disposed across the longitudinal directions of the segments and the slits, in which the diameter of the reaction area is defined as a crucible diameter, the crucible diameter is 100 to 300 mm, and gaps of the slits are defined by

[00001]$d_{\mathrm{slit}}0.3\frac{}{50}$

(mm)(where d.sub.slit is the gap between the slits and is the crucible diameter).

A metal oxide barrier and a connecting method for solving the problems in which sectors of an existing cold crucible are connected by means of a mica plate and the mica plate is damaged due to arcing and the like and in which the sectors are strongly connected by means of the mica plate and thus are difficult to replace and maintain. A cold crucible, comprising a metal oxide barrier, according to the present invention can prevent arcing, enables reduction of damage on the edge part of a water cooling sector due to a molten material and thus enhances durability. Moreover, the metal oxide barrier can easily be replaced compared to an existing mica plate and thus enables easy maintenance and repair.

A cold crucible may include a plurality of fingers extending in an axial direction and arranged in a circumferential direction, and a slit between each pair of adjacent fingers. The cold crucible may also include at least one insert in each of the slits. The at least one insert may include a first component made of a soft magnetic composite material, and a second component made of a soft magnetic component.