JPS60114391A - Removing method of silica in water - Google Patents

Abstract

PURPOSE:To remove effectively silica contained in water with a simple installation and operation by bringing the thioether polymer expressed by the specified general formula into contact with water contg. silica and separating the polymer phase and the water phase. CONSTITUTION:The thioether polymer expressed by the formula [in which, A, B may be the same or different and denote respectively -H, -SH, -X (X denotes halogen atom), n, m denote respectively the numbers satisfying 4<=m<=2, 5<=n<= 200] is charged into the silica-contg. water stored in a tank or the silica-contg. water flowing in a pipe and the water is stirred and mixed. The amt. of the thioether polymer may be increased or decreased according to the concn. of silica. The contact time between said polymer and the silica-contg. water is such time when the concn. of the silica in the water after the treatment is <=200ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for removing silica components present in water, and more particularly to a method for removing silica in water using a thioether polymer.

[Technical background of the invention and its problems]

Natural water, especially hot water pumped up from underground during geothermal utilization, contains large amounts of soluble silica and colloidal silica.

As a result, silica precipitates as scale in piping systems and equipment that utilizes hot water, often causing blockage accidents in piping and equipment.

Measures to prevent such accidents include adding various cationic components to the natural water being pumped, charging colloidal silica to suppress precipitation, and adding various flocculants and silica scavengers. A method has been adopted in which the material is then subjected to precipitation separation and centrifugation treatment.

However, all of the above methods have problems in that the operations are complicated and the processing takes a long time.

[Purpose of the invention]

The present invention aims to solve the above problems and provide a method for effectively removing silica contained in water using simple equipment and operations.

[Summary of the invention]

The method of the present invention is based on the following formula: A÷(CH2) mS sludge B (wherein A and B may be the same or different,
Each represents -H, -8H, -X (where X represents a halogen atom); m and n each represent 4≦m≦2
The method is characterized in that after a thioether polymer represented by the formula (representing a number satisfying the relationship of 0,5≦n≦200) is brought into contact with silica-containing water, the polymer and water are separated.

The method of the present invention has the greatest feature in using the above-mentioned thioether polymer.

This thioether polymer has +(CH2)m-8+ as a repeating unit, and its terminal ends are -H and -8H.

-X (where X represents a halogen atom). That is, the above formula % formula % exists. Further, A and B may be the same or different. X may be any halogen atom, but from the viewpoint of ease of manufacturing the thioether polymer, X is preferably Br or Cl.

The number m of methylene groups in the repeating unit is 4 or more and 20 or less. When m is less than 4, the polymer becomes liquid and becomes difficult to handle, and when m exceeds 20, the polymer becomes
The melting point increases and the content of sulfur atoms decreases, resulting in
The effect becomes smaller.

Preferably it is 5-12.

Furthermore, the number n of repeating units described above is 5 or more and 200 or less. When n is less than 5, it is disadvantageous because it is easily miscible with water and difficult to separate from water.
If it exceeds 100%, sufficient silica trapping effect will not be exhibited. Preferably it is 7-100.

Such thioether polymers are X (CH2) m-
It can be easily produced by using as starting materials X (where X is Cl), Na, S, and water and polymerizing them using a catalyst.

The method of the present invention is carried out as follows.

That is, first, the above-described thioether polymer is brought into contact with silica-containing water. The contact may be made in any manner. For example, the polymer is added to silica-containing water stored in a tank or flowing through a pipe, and stirred and mixed.

The amount of the thioether polymer to be used cannot be determined uniquely because it can be increased or decreased depending on the silica concentration. Further, the contact time between the polymer and the silica-containing water is determined depending on the amount of the polymer used, the silica concentration of the raw water, and the silica concentration of the water after treatment.

Usually, the time is such that the silica concentration in the water after treatment becomes 200 ppm or less.

The temperature during this contact is not particularly limited, but if the contact is made at a temperature higher than the melting point of the thioether polymer, that is,
When the thioether polymer is used in a molten state, the silica removal effect is significantly improved and effective.

In this way, the silica in the silica-containing water is trapped by the thioether polymer. The thioether polymer entrapping the silica is present as a precipitate or dispersed in the water after treatment.

Therefore, in the present invention, next, the thioether polymer phase in which silica has been trapped and the water phase are separated.

When separating both phases, use conventional solid-liquid separation (separate P in precipitate).
, liquid-liquid separation (when the polymer is molten) treatment, etc. may be performed as appropriate.

[Embodiments of the invention]

Example 1 Formula: H8-E-(CHI)6- with a molecular weight of about 1000
20 g of powder of a thioether polymer (melting point 76°C) represented by S + Fr1H was mixed with colloidal silica content of 792
It was poured into 100 d of raw water with a total silica content of 940 ppm. After shaking the polymer powder and raw water system at a temperature of 25° C., the powder was separated from P and the colloidal silica content and total silica content in the treated water were measured.

The results are summarized in Table 1 as a relationship with shaking time.

Table 1 Example 2 +:1rx-fk polymer has formula: HSMo(Cut)to
Silica in the raw water was removed in the same manner as in Example 1, except that it was 5thH (molecular weight approximately 11,000, melting point 96°C). The results are shown in Table 2.

Table 2 Example 3 The temperature at the time of contact with the raw water was 100°C, except that the separation method was to leave the entire treatment system still and separate the organic phase and the aqueous phase. Silica was removed in the same manner as in Example 1. After 10 minutes of contact time, the contents of colloidal silica and total silica were 14 ppm and 2 ppm, respectively.
It was 73 ppm.

Example 4 Silica was removed in the same manner as in Example 2, except that the temperature during contact with raw water was 100°C. After a contact time of 10 minutes, the contents of colloidal silica and total silica were 21 ppm and 284 ppm, respectively.

Example 5 Formula 'H8+(CHt)eS+f-H (molecular weight approximately 4200.

Silica in the raw water was removed in the same manner as in Example 1, except that a thioether polymer having a melting point of 42°C was used and the temperature during contact was 50°C. After a contact time of 10 minutes, the contents of colloidal silica and total silica were 15 ppm and 301 ppm, respectively.

〔Effect of the invention〕

As is clear from the above explanation, the method of the present invention has the following effects: 1. Silica in water can be removed with extremely simple operation and equipment; 2. The time required for silica removal is relatively short.
It has great industrial value when applied to industries that directly use natural water, geothermal power generation, mining-related fields, etc.

Claims (1)

[Claims] 1. The following formula: A 1,000 (CH2) m 5-)-B (in the formula, A
, B may be the same or different, and each -
H, -8H, -X (where X represents a halogen atom); m and n are 4≦m≦20, 5≦n, respectively
A method for removing silica in water, the method comprising: contacting a thioether polymer (representing a number satisfying the relationship of ≦200) with silica-containing water, and then separating the polymer phase and the water phase. 2. The method according to claim 1, wherein the temperature during the contact is higher than the melting point of the thioether polymer.