SU753834A1 - Charge for producing refractory articles - Google Patents

Description

The invention otm: ITs to the technology of manufacturing carbon types of products and will find application in the electrode industry in the production of carbon refractories for lining blast furnaces and ferroalloy furnaces, and coal elec- trodes. The refractory material is resistant to oxidation at a temperature of 1000IBOO C under conditions of high-temperature gas flows in the following ratio of components 1. Silicon carbide 47-51 Pyrocarbon38-42 Carbon fiber 5.5-6.5 Silicon1, O-1.5 Bor3.5-4 , 0. However, it is impossible to manufacture a carbonaceous product from such a large composition (55Ox55Ox1600) by precipitating pyrocarbon on it and impregnating it with a mixture of silicon and boron; The hehnshlogic progreso process is complex and lengthy (13 days). The closest technical solution to the invention is composition 2, containing calcined anthracite, graphite graphite and coal tar pitch in the following ratio, wt.%: Calcined anthracite 68-72 Artificial graphite3-7 Coal carbon23-27 Formed from this mixture, the electrodes and blocks are roasted in a non-oxidizing gas atmosphere at a temperature of 12OO-125O and after machining, they are used for lining blast furnaces and ferroalloy furnaces. Carbonaceous products from the specified composition of the mixture have the following characteristics: Mechanical compressive strength, kg / cm 275-35 O Oxidation rate in the reaction medium (in a current of CO2 at 5 O-65 1000 C) Porosity is open,% Total porosity,% 2 O-23 Limiting factor in increasing the service life of carbon refractories and reducing their consumption is the resistance to oxidation in the reaction medium. The aim of the invention is to increase the resistance to aggressive gases, increase mechanical strength and decrease porosity. For DOS 344 containing calcined anthracite, artificial graphite and coal tar pitch, additionally contains boron carbide in the following ratio, wt.%: Artificial graphite20-27 Coal tar17-18 Boron carbide1-5 Calcined anthraciteEverything Else

Artificial

graphite

Coal

pitch

Coal

coke

Boron carbide Raw materials Thermoanthracite: True density, g / cm Ash content,% Electrical resistivity, cm. Mm 2 / M Artificial graph True density, g / cm

Ash content,% Carboniferous ne Dimension temperature.

23

20

20

18

18

18

6

Ash content

1.33

%

Carbite boron:

Carbide content

boron,% 87

The prepared mixture is stirred while heating to 135-140 ° C in a Z-shaped mixing machine with a volume of 10 liters. Mixing time - 60 min. Then molded articles with a diameter of 60 mm forcing through the mouthpiece. After cooling, the product is fired in a non-oxidizing atmosphere at a temperature. The resulting products have the following physical and mechanical characteristics:

Table 2

Table 2 presents the characteristics of the products manufactured by the known composition and composition of the invention.

As can be seen from the table, the resistance in the current of aggressive gases for compositions additionally containing boron carbide increases and exceeds significantly the same values as the prototype. This reduces the open porosity and increases mechanical strength. The proposed composition allows to obtain higher quality products, the durability of which in a hostile environment increases 10 times: the open porosity decreases 2 times and the mechanical compressive strength increases by more than 25%; F o r mula inventions

The mixture for the manufacture of refractory products containing calcined anthra. Continued table. 2

UrfT, artificial graphite and coal tar pitch, characterized in that, in order to increase resistance to aggressive gases, and increase mechanical strength and decrease porosity, it additionally contains boron carbide in the following ratio of components, wt.%:

Artificial graphite2 O-27

Coal tar 17-18

Boron carbide1-5

Calcined anthracite Else

Sources of information taken into account in the examination

1. USSR author's certificate

No. 5677О8, cl. C O4 B 35/52, 1976.

2. USSR author's certificate

No. 536664, cl. From O1 To 31 / O2, 1975, unpub.

Claims (1)

Claim A mixture for the manufacture of refractory products containing calcined anthracite, artificial graphite and coal tar pitch, characterized in that, in order to increase resistance to aggressive gases, and increase mechanical strength and reduce porosity, it additionally contains boron carbide in the following ratio of components, weight.%: Artificial Graphite Coal Pitch Boron Carbide Calcined Anthracite 20-27 17-18 1-5 Rest