SU535349A1 - The outer layer of the briquette - Google Patents

Description

(54) EXTERNAL BRIQUETTE LAYER

This invention relates to the field of metallurgy and foundry.

Protective coating compositions of low-boiling powders for the treatment of cast iron based on fireclay refractory material containing cast iron chips, chlorine: potassium and liquid glass 1 are known. Such compositions have insufficiently high mechanical strength and a tendency to cracking when they are immersed in liquid iron. magni.

iB aims to increase mechanical strength at high temperatures (magnesium evaporates at 1107 ° C) into the proposed outer LAYER of briquette calcium hydroxide is introduced in the following ratio of components, weight. %:

Iron shavings Liquid glass

(spd weight 1.48 g / cm) Potassium chloride Calcium hydroxide (Fireclay

The addition of calcium hydroxide provides an increase in the strength properties of the protective coating at high temperatures (higher than 1000 ° C) and improves the sintering of the mixture. When loading a protective coating up to 800

1000 ° C, a ternary compound Na2O is formed. CaO SiO2, which increases the strength of the protective coating at high temperatures.

The optimum content of the calcium hydroxide additive () was established during experiments to obtain the maximum strength of the coating when it was introduced into liquid iron.

The preparation of a magnesium modifier briquette with a protective coating of the composition proposed is carried out as follows.

An iB blender alternately loads the bulk components: chamotte (particle size 0.5-4 mm), cast iron chips, potassium chloride and calcium hydroxide, which are mixed to obtain a homogeneous dry mass. Liquid glass is then poured and mixing continues until it is evenly distributed throughout the mixture. The finished mixture is fed to the molding. The size and shape of the briquette are determined by the amount of the additive to be added when the thickness of the protective coating is 10-30 mm. The magnet magnet is molded into the middle of the briquette. Ready (the briquette undergoes short-term drying at 100-130 ° С and, having acquired strength sufficient for transportation, goes to

0 liquid iron treatment area. Briquette

forcibly immersed in the bottom of the ladle with liquid iron. The protective coating does not deteriorate through the skin, and the pores in it gradually let go of the forage, the pair of magnesium.

iB laboratory conditions, the protective coating was tested on the input of metallic magnesium as an example to obtain nodular cast iron. Stable results were obtained on the absorption of magnesium by cast iron (+ 0.00.1%).

iB tab. 1 shows the compositions of the known (1) and proposed (2 and 3) coatings.

Table I

| In Table. 2 shows the mechanical properties of these pok, ryty.

table 2

Claims (1)

Invention Formula The outer layer of the magnesium briquette modifier for cast iron processing contains chamotte, water glass, cast iron chips and potassium chloride, characterized in that in order to increase the mechanical strength of the coating and the stability of the absorption of magnesium iron, calcium hydroxide is added in the following ratio of components, wt. %: Cast iron chips 10-20 Liquid glass 13-17 Potassium chloride 3-5 5-9 Calcium Hydroxide Chamotte Rest The source of information taken into consideration by the expert is I. US Patent No. 3598575, Cl. 75-130, 1969