JPS6037844B2 - Desulfurization agent for hot metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a desulfurizing agent for a hot metal gun, and particularly to a desulfurizing agent for hot metal containing lime and residual aluminum ash.

Conventionally, lime-based desulfurization agents such as quicklime, limestone, and limestone have been known, but since these have lower desulfurization ability than calcium carbide, it is desired to improve their desulfurization ability.
The present invention is a desulfurization agent containing quicklime and residual aluminum ash, and proposes a lime-based desulfurization agent that can effectively* utilize the raw material of aluminum production.

The first invention of the present invention contains quicklime and aluminum residual ash at a ratio of 30 to 70% and 70 to 30% by weight, respectively, and the second invention contains B203 in the mixture of the first invention.
It is characterized in that it contains 1 to 1% by weight of the containing substances.

The main component of the desulfurizing agent of the first invention of the present invention is Ca○, and C
Ordinary quicklime with an aq purity of 9% by weight or more is used.

It is preferable that lime contains substantially no attached moisture, but the inclusion of hydroxide does not pose any particular problem as a desulfurizing agent. Next, aluminum residual ash is a byproduct generated during aluminum manufacturing.

An example of its composition is shown in Table 1. Further, the aluminum residual ash may be in powder form, but it is preferable that the particle size is 100 grains or less.

Table 1 (Chemical composition) AI component in aluminum residual ash is AIN
, AI, AI203, etc.

Since the proportion thereof varies depending on the amount of water contained therein, when adding alumina residual ash to quicklime, it is desirable to use one that does not substantially contain water. In the present invention, the mixing ratio of quicklime and aluminum residual ash is 3
0-7% by weight and 70-3% by weight.

If the proportion of aluminum residual ash is less than 3% by weight, it will not be possible to improve the desulfurization properties of quicklime, and if it exceeds 7% by weight, the residue after desulfurization will become extremely solid, resulting in poor meltability. Semi-molten slag is not preferred because it may cause blocking phenomena. To manufacture the product of the present invention, the powders of quicklime and aluminum residual ash may be simply mixed together, or the two may be mixed and ground.

The desulfurizing agent according to the present invention preferably has a fine particle size, but
For example, if it is 100 μm or less, a sufficient desulfurization effect can be achieved.

The second invention of the present invention is to add 1 to 1 part of the B203-containing substance to 10 parts by weight of the above-described mixture of quicklime and aluminum residual ash.
By using this, the melting properties of the desulfurizing agent can be further improved.

Specific examples of substances contained in B203 include perishite, terrace sand,
Examples include powders such as shelf acid.

If the amount added is less than 1% by weight, it is difficult to sufficiently improve meltability. Moreover, when it exceeds 1% by weight, the amount of quicklime decreases relatively and the desulfurization ability decreases. B20
It is preferable that the substance contained in No. 3 contains substantially no attached moisture. The presence of adhering moisture digests the quicklime and reduces desulfurization ability, so it is necessary to dry it thoroughly before use. The desulfurization agent of the present invention improves the desulfurization capacity and the meltability of slag compared to conventional lime-based desulfurization agents, and furthermore, it enables effective use of aluminum residual ash, which is industrial waste. This is useful in terms of resource saving and cost reduction.

Hereinafter, the present invention will be further explained with reference to its implementation.

Example 1 Quicklime with a calcium concentration of 95% by weight and dried aluminum ash shown in Table 1 were blended in the proportions shown in Table 2,
The desulfurization agent of the present invention was manufactured by pulverizing and mixing in a pulverizer to a particle size of 100 French or less.

Next, 0.5% by weight of this desulfurizing agent was added to the hot metal, and desulfurization treatment was carried out at a temperature of 1400 qo for 1 hour in a high-frequency furnace while being heated.

The results are shown in Table 2. Furthermore, experiment no. 1 to 3 are Examples, Experiment No. 4 to 6 are comparative examples. Table 2 Examples
2. Grain size 100 or less perishite (Xa0, coarse 2Q, 8LO)
Experiment No. of Example 1. The same procedure as in Example 1 was conducted except that the desulfurization agent was blended in the ratio shown in Table 3 with respect to 10 parts by weight of the mixture of 2 and 2.

The results are shown in Table 3.

Table 3

Claims (1)

[Claims] 1. Quicklime and aluminum residual ash are each 30 to 70% by weight.
A desulfurizing agent for hot metal containing 70 to 30% by weight of. 2 Quicklime and aluminum residual ash are each 30 to 70% by weight
A desulfurizing agent for hot metal, comprising 1 to 10 weight % of a substance containing B_2O_3 to 100 parts by weight of a mixture containing 70 to 30 weight % of B_2O_3.