JP3044610B2 - Purification method of diatomaceous earth filter aid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a purification technique for removing impurities in diatomaceous earth for use as a diatomaceous earth filter aid. Used for purification of diatomaceous earth filter aid with reduced eluting iron content.

The term "filtering aid" refers to a substance which promotes efficient filtration by preventing or clogging a filter medium and reducing filtration resistance by adhering or incorporating a substance to be filtered such as a colloidal substance.

[0003]

2. Description of the Related Art Diatomaceous earth is formed by accumulating fine diatom husks mainly composed of silicic acid to form a mineral sedimentary layer. It is necessary to remove impurities such as organic substances.

[0004] For this purpose, the conventional means is to pulverize and dry diatomaceous earth ore, remove sand and fine clay components with a water gutter, transfer it to an acid-resistant reactor, and add hydrochloric acid and sulfuric acid. And then heat-treat for several hours.
Next, a large amount of water is added, the mixture is stirred and allowed to stand, the supernatant is discarded, and washing with water is repeated sufficiently, followed by filtration, dehydration and drying. Furthermore,
Infiltrate a small amount of urea or ammonium salts, 800 ° C
Thus, the filter aid is manufactured quantitatively by heating for several minutes. For these production, a production process by a batch operation is known.

[0005] In the above-mentioned prior art, since an inorganic acid is used for the diatomite impurity removal treatment, anions such as chlorine and sulfur may remain, and impurities such as iron contained in the diatomite may be insufficient. , It remains as a soluble component in water, alcohol, organic acids and the like. Further, manufacturing processes such as removal of sand and clay by a water gutter, heat treatment with an inorganic acid, washing with water, dehydration, and drying have a drawback that automated continuous operation is difficult due to each batch operation.

[0006]

The problem to be solved by the present invention is that a metal such as iron contained in diatomaceous earth ore is made soluble in water by an organic acid and does not contain a metal such as iron by solid-liquid separation. A diatomaceous earth is obtained, and an organic acid is recovered and reused in a deironing reaction, thereby enabling continuous operation.

[0007]

In order to solve the above-mentioned problems, the present invention comprises treating diatomaceous earth with an organic acid to convert a metal in impurities in the diatomaceous earth into a soluble metal chelate compound, and solidifying the metal chelate compound. The object is achieved by removing by a liquid separation and recovering the remaining organic acid by an electrodialysis method.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In practicing the present invention, a diatomaceous earth ore is crushed and dried to activate a reaction of a metal such as iron on the surface of diatomaceous earth particles as a raw material, and the diatomaceous earth ore is 700 to 13 mm
Bake at 00 ° C. An organic acid is used as an acid having a strong binding force with a metal such as iron on the surface to form a chelate complex by a deironing reaction. The diatomaceous earth containing the chelate complex is washed with water to remove soluble substances, and dehydrated and dried. Further, the organic acid aqueous solution used in the deironing reaction is collected, and the organic acid aqueous solution is regenerated by electrodialysis, and used repeatedly in the deironing reaction. This enables continuous production of the filter aid.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS To explain a detailed embodiment of the present invention, diatomaceous earth ore obtained from Yorinosawa mine, Moriyoshi-cho, Kitaakita-gun, Akita Prefecture was used. The ore was pulverized, classified to 1.2 mm or less, and dried at 110 ° C. for 2 hours. This is 700 ~ 13
The material fired at 00 ° C. for 2 hours or more was used as a raw material. on the other hand,
In an acid-resistant reaction tank, 25 liters of an aqueous solution of oxalic acid having a concentration of 0.1 to 5 N as an organic acid aqueous solution was prepared, and 2500 g of diatomaceous earth as a raw material was added thereto. To perform a deironing reaction. While maintaining a constant temperature, a chelate complex is formed by a deironing reaction for 0.5 to 4 hours. After the completion of the reaction, a slurry of diatomaceous earth and an aqueous oxalic acid solution containing leached iron is put into a filter cloth and filtered by centrifugation. The diatomaceous earth that has undergone the iron removal reaction is washed with water to remove any remaining soluble substances such as oxalic acid aqueous solution containing residual leachable iron, and then thoroughly dehydrated by centrifugation, transferred to a rotary dryer and dried completely to quantitatively determine Manufactures filter aids. Further, an aqueous solution of oxalic acid containing impurities such as leached iron used in the deironing reaction is collected, separated into impurities such as iron and aqueous oxalic acid by electrodialysis, and the aqueous oxalic acid solution is regenerated. The regenerated oxalic acid aqueous solution is sent to an acid-resistant reaction tank, and is repeatedly used in a deironing reaction.

[0010]

According to the present invention, the produced filter aid is suitable for filtration of sake, juices, soy sauces, fats and oils, etc., because it has a small amount of substances soluble in water, alcohols, organic acids, etc. Since the amount of iron eluted by the alcohol-eluting iron test of the filter aid test method is very small, the filtrate can be filtered without impairing the taste, color, and aroma of sake, and its use as a filter aid for brewing is expanded. There is.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noboru Takahashi No. 4 at Shinyacho, Akita-shi, Akita Prefecture 11 at the Industrial Technology Center in Akita (72) Inventor Moto Kudo Inouya, Shinya-cho, Akita-shi, Akita No. 4 at 11 Akita Prefectural Industrial Technology Center (72) Inventor Osamu Nomura 2-1-252 Nakadori, Akita City, Akita Pref. Akita Public Health Center (56) References JP-A-54-77376 (JP, A) JP-A-6-315368 (JP, A) JP-A-49-128886 (JP, A) JP-B-50-22511 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 20 / 14 B01D 39/06 B01J 20/30 B01D 39/00

Claims (2)

(57) [Claims] 1. A method for purifying a diatomaceous earth filter aid, comprising: treating diatomaceous earth with an organic acid to convert an impurity metal in the diatomaceous earth into a soluble metal chelate compound; and removing the metal chelate compound by solid-liquid separation. 2. A diatomaceous earth characterized in that diatomaceous earth is treated with an organic acid to convert a metal of an impurity in the diatomaceous earth into a soluble metal chelate compound, the metal chelate compound is recovered, and the organic acid is recovered and used by electrodialysis. Purification method of filter aid.