JPH02298366A - Grinding adjuvant of mineral substance - Google Patents

Abstract

PURPOSE:To obtain sufficient grinding effect in spite of a low addition rate by using an aqueous liquid of a high condensate of ethylene glycol based on tetraethylene glycol as a grinding adjuvant of mineral substance. CONSTITUTION:As the grinding adjuvant in a grinding process of hydraulic mineral such as Portland cement or shaft furnace slag, an aqueous liquid of a high condensate of ethylene glycol based on tetraethylene glycol or pentaethylene glycol is used. As the aqueous liquid, the residual liquid obtained by distilling off a synthetic product after the synthesis of ethylene glycols by an ethylene oxide method is used. This grinding adjuvant shows sufficient grinding effect in a small addition amount and the pack set index thereof is also good.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention improves the pulverization efficiency in the pulverization process of hydraulic minerals such as Portland cement, blast furnace slag, alumina cement, fly ash, limestone, and gypsum. This invention relates to a grinding aid for mineral substances to prevent reagglomeration during transportation and storage of powdered minerals.

[Conventional technology]

Conventionally, mineral materials, especially Portland cement clinker-5
When grinding blast furnace slag and the like, grinding aids such as diethylene glycol and triethanolamine are used to increase grinding efficiency.

In the grinding process, it is desirable to reduce the mineral material to the desired particle size as efficiently as possible and at a relatively fast rate.

in general,! Grinding the material causes disintegration of the W material particles and exposes fresh active surfaces. This surface probably has high energy due to the breaking of ionic bonds. The surface force of the crushed particles is maintained for a certain period of time after crushing, and if this force is not reduced or eliminated, the powder may become compacted or bank cent, resulting in poor flowability.

Punccent refers to "powder agglomeration" in which, for example, when powder is stored or transported in bags, powder particles agglomerate and adhere to each other due to their surface forces. In the present invention, the ease with which agglomerated powder particles begin to reflow is expressed as a relative value called "backset index." For example, when mineral powder is loaded directly into a hopper car, the powder particles often become solid clumps. This agglomerated powder becomes particulate and does not flow unless a significant mechanical impact is applied to break this state.

Recently, various grinding aids have been actively used in the grinding of Portland cement clinker and blast furnace slag. Traditionally, triethanolamine, diethylene glycol,
Aniline, p-toluidine, m-phenylenediamine,
Dimethylaniline, diphenylaniline, 2.4.6-
) Ribromoaniline, N-phenylhydroxyamine, β-phenethylamine, morpholine, pyridine, piperidine, virol, pyrrolidine, viroline, pyridazine, pyrimidine, N-methylmorpholine, dimethylpyridine, dimethylethylpyrrole, piperazine, pinzole resin, resorcin, lignin Sulfonate salts, oxycarboxylate salts, etc. are known.

[Problem to be solved by the invention]

However, the grinding aids that have been researched and used in the past have limitations in improving grinding efficiency, and if a large amount of grinding aids are used in order to improve the grinding effect, the problem is that grinding costs will increase. was there. Therefore, there has been a need for a grinding aid that is more easily available and has significant effects in small amounts.

[Means to solve the problem]

The present inventors have conducted extensive research to solve the above-mentioned problems, and have developed a high condensate of ethylene glycol containing at least one of tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, and heptaethylene glycol as a main component. The aqueous liquid it contains is effective as a grinding aid for mineral materials, and this aqueous liquid is the residual liquid obtained by distilling off the synthesized product after synthesizing ethylene glycols from ethylene oxide and water using the so-called ethylene oxide method. It has been discovered that this can be used as an excellent grinding aid, leading to the completion of the present invention.

In one embodiment, the mineral grinding aid of the present invention is an aqueous liquid prepared from a high condensate of tetraethylene glycol or pentaethylene glycol.

That is, tetraethylene glycol or pentaethylene glycol is used as it is or as an aqueous liquid diluted with water to about 2 to 30 times.

In another embodiment of the mineral grinding aid of the present invention, when ethylene glycols are synthesized from ethylene oxide and water by the ethylene oxide method, the residual liquid obtained by distilling off the synthesized product after the synthesis is used. According to the research conducted by the present inventors, an example of the analytical values of the residual liquid is shown in Table 1.

(Margin below) Table 1 (Note) *1: Based on the floating scale method.

*2: Based on B type viscosity needle.

As can be seen from the results shown in Table 1, the main components of the extraction residue were tetraethylene glycol and pentaethylene glycol (-85% by weight in total).

In other words, in the ethylene oxide method, in addition to producing ethylene glycol, diethylene glycol, triethylene glycol, etc. through the reaction of ethylene oxide and water, tetraethylene glycol and pentaethylene glycol are also produced as by-products. After certain ethylene glycol, diethylene glycol, triethylene glycol, etc. are distilled off, a large amount of by-product tetraethylene glycol and pentaethylene glycol remain in the residual liquid. Therefore, the method of using the residual liquid in this ethylene oxide method is industrially and economically preferable.

The grinding aid of the present invention is added dropwise or by spraying to the material to be ground before or during the grinding of the mineral material. Further, it is added in an amount of 0.002 to 0.1% by weight, preferably 0.005 to 0.05% by weight, based on the material to be crushed.

[Effect]

The grinding aid of the present invention has a larger molecular weight than conventional grinding aids and is effective in preventing aggregation of powder, and a sufficient effect can be obtained by adding a small amount.

〔Example〕

9 pieces of Portland cement clinker - 2.5 kg, 2 pieces of gypsum 75 g - crushed in a porcelain ball mill with a capacity of 6.81 kg
The various grinding aids shown in Table 2 were added as grinding aids at the addition rates shown in Table 2, and the grinding process was carried out for 6 hours. The obtained samples were designated as "Sample 1" to "Sample 3", respectively.

Comparison A: Grinding experiments were conducted in the same manner as in the above examples, except that conventional ethylene glycol and water were used as grinding aids. The obtained samples were designated as "Sample A" and "Sample B."

The samples obtained in the above Examples and Comparative Examples were subjected to a fineness test, a flow test, and a compressive strength test according to JIS-
It was carried out in accordance with R5201. Furthermore, the punccent index was measured and these results are also listed in Table 2.

In addition, the pack set index was measured by the following method.

Put 100 g of the powder sample into an Erlenmeyer flask (capacity: 250 ml) mounted on a variable vibrator, vibrate it for 15 seconds, remove the Erlenmeyer flask from the vibrator, and gently tilt it so that its center (center axis of the opening) ) was placed horizontally on the jig. Next, in this state (while keeping the center horizontal), rotate the flask at an angle of 180 degrees around its center at a rate of 100 revolutions per minute, and calculate the number of 180 degree rotations required to collapse the sample inside. This is the punk set index. Therefore, the smaller the Punxet index value is, the easier the powder is to handle with less agglomeration.

From the test results for each sample listed in Table 2, it was found that the grinding aid according to the present invention exhibits better performance in small amounts.

〔Effect of the invention〕

According to the present invention, a sufficient pulverizing effect can be obtained with a small addition rate, the pack cent index is also good, and the residual liquid after producing ethylene glycol, diethylene glycol, and triethylene glycol can be used by the ethylene oxide method. This is an extremely useful invention that helps in the effective use of resources.

(Margin below)

Claims (2)

[Claims] (1) A mineral grinding aid consisting of an aqueous liquid containing at least one of tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, and heptaethylene glycol. (2) A mineral grinding aid consisting of the residual liquid obtained by reacting ethylene oxide and water to synthesize ethylene glycol, diethylene glycol, and triethylene glycol, and distilling off the synthesized products.