JPS5939387A - Neutralizing agent - Google Patents

Abstract

PURPOSE:To obtain the titled neutralizing agent having the excellent efficiency of neutralization without the need of mechanical agitation, by forming a mixture comprising a calcium neutralizing agent and a salt composed of an atom or an atomic group other than Ca or SO4. CONSTITUTION:The mixture comprising a Ca neutralizing agent (e.g. slaked lime or calcium carbonate) and a salt (e.g. NaCl) composed of an atom or an atomic group other than Ca or SO4 is formed in the presence or absence of a binder (e.g. cement) to obtain the neutralizing agent. This neutralizing agent is esp. suitable for neutralizing sulfuric acid water flowing out of an unmanned unworked or abolished mine, etc. difficult to receive an electric power source. By the presence of said neutralizing agent in the outflow sulfuric acid water, neutralization can be unmannedly realized with high efficiency for over a long time without the need to use driving power, even if mechanical agitation is not completely performed. Thus, the prevention of environmental pollution can be effectively realized while saving installation, labor and driving power.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a neutralizing material particularly suitable for neutralizing sulfuric acid water.

Conventionally, sulfur [fl] water is neutralized using neutralizing agents such as slaked lime, calcium carbonate, caustic soda, and ammonium hydroxide, but in the case of mine drainage where a large amount of water is to be treated, VC
Inexpensive calcium-based neutralizing agents such as slaked lime and calcium carbonate are often used. However, when using calcium-based neutralizing agent gold for sulfuric acid acid water, there were some problems in the neutralization process. This is followed by a neutralization reaction.
F- is often caused by a Ca5O4Vc base. That is, since the solubility of CaSO4 in water is low, a thin layer of 0aSO4 is formed on the surface of the neutralizing agent, which inhibits the neutralization reaction. This precipitation [0aSO4 also lowers the neutralization reaction rate and reduces the efficiency of the neutralizing agent, so the size of the neutralization equipment must be increased and the amount of neutralizing agent used must also increase. This π above 0aSO4
Normally, the entire liquid is mechanically stirred in order to completely remove the thin layer and carry out the neutralization reaction efficiently, but in this case! cid
In addition to increasing equipment and power costs, mechanical agitation is virtually impossible in cases such as unmanned decommissioned mines where sulfuric acid acid water is generated little by little. There is a strong need for an economical treatment method that does not cause such problems.

Does the present invention meet such requirements? The overall purpose was to provide a highly efficient neutralizing agent, and as a result of various tests and studies for this purpose, we found that calcium-based neutralizing agents
i or atoms or atomic groups other than SO4;2)>u;'z
We were able to develop a new neutralizing material by mixing salts and forming them into a lump in the presence or absence of a binder. Here, the Cal/Rum neutralizer is a normal neutralizing agent such as thorn, slaked lime, and calcium carbonate.
2003. Mgct2゜Ligni/Sulfonate, Na
ct, etc., but a typical example is 1″tNact.
i can list.

The mixture may be formed into a block of an appropriate size by compression molding or other methods, but the strength can also be increased by using a binder such as cement.

When sulfuric acid acid water is neutralized using the neutralizing material (neutralizing ball) according to the present invention, as shown in the examples below, when neutralizing with a calcium-based neutralizing agent alone, vr-f Even without stirring, the neutralization efficiency is significantly improved.

This is thought to be because the salts consisting of atomic groups spanning atoms other than Ca and SO4 in the neutralized material of the present invention serve to completely inhibit the precipitation of CaSO4 on the surface of the bulk material.

This effect is fully manifested even when the neutralized material of the present invention is completely combined using a cement/torer, and even without mechanical stirring, it is possible to efficiently combine not only the surface of the bulk neutralized material but also the center. It can react well.

Therefore, the neutralizing material of the present invention is particularly suitable for neutralizing sulfuric acid water that flows out from unmanned abandoned mines where it is difficult to obtain a power source. If a neutralizing material is present, it is possible to carry out the neutralization process efficiently without any mechanical agitation, and it is possible to realize unattended, non-powered, long-term neutralization process, and to prevent pollution. It can be implemented effectively with less equipment, less labor, and less power.

Example 1 A case in which sulfuric acid acidic water 41 with a pH of 4.0 was neutralized with one block neutralizer consisting of slaked lime 277 and cement 67, and a block neutralizer consisting of slaked lime 277, cement 6 and table salt 202. Elapsed time and p when neutralized with one Japanese additive
I looked up the sounds related to H. The results are shown in Figure 1. This result shows that the neutralization rate of the bulk neutralizer containing salt is significantly faster.

! , 1ζ, 4 tVC of sulfuric acid acid water with pH 3.7, neutralized with two bulk neutralizers consisting of slaked lime 272 and cement 62, and slaked lime 271, cement 59 and common salt 2
The relationship between the elapsed time and pH when neutralizing with two bulk neutralizers consisting of 07 and Katana 1 was as shown in FIG. 2.

It can be seen that the neutralization rate of the block neutralizer containing Yapori salt is significantly faster.

Example 2 Five types of bulk neutralizers having the compositions shown in Table 1 below, pH 4,
A neutralization test was conducted by preparing 0 sulfuric acid acid water.

Table 1 (a) The relationship between elapsed time and pH when 41 VC of sulfuric acid acidic water having a pH of 4.0 was neutralized with two pieces of bulk neutralizing agent A is as shown in FIG. 6 (a) Vc. At points a and b, each of the bulk neutralizers cracks and breaks, and the pH rises rapidly in the vicinity; The degree of consolidation is also poor.

(b) When 4 tons of sulfuric acid acidic water with a pH of 4.0 is neutralized with 82 bulk neutralizers, as shown in Figure 3 (b) Vc,
pH 7, OVc reached in 50 minutes, 7m. Neutralized water f pH4
,0 Nosulfuric acid acidic water 4tvc replaced, pH 7 in 95 minutes,
It reached 0Vc. Add neutralized water again to sulfuric acid acid water with pH 4.0
When tVC was replaced, pH reached 7.0 IC in 105 minutes. Compared to the VC shown in Figure 6 (a) which does not contain any salt, the neutralization rate is significantly improved and the service life is longer.

(c) In the same manner as in (b), two pieces of block neutralizer 0. D
The results of neutralizing 4 tons of sulfuric acid acidic water with a pH of 4.0 with E and E four times each are shown in Figures 5 (C), 3 (d), and 3 (e), respectively.
c showed. If the addition of salt increases, A→B −+
O and neutralization rate tend to increase, but C! ,D,E
No major differences were observed between them.

[Brief explanation of the drawing]

Figure 1 is a graph of the pH change over time of the conventional neutralizing agent VC, 1:
FIG. 2a is a graph of pH change over time using the neutralizing material of the present invention, and FIG. 3a is a graph of pH change over time when the type and amount of the neutralizing material of the present invention are varied.

Claims (1)

[Claims] <11 Calcium-based neutralizer and Ca or H so4
A neutralizing material made by molding a mixture of a salt composed of atoms or atomic groups other than those of other atoms and a swordsmith in the presence or absence of a binder. (2) The neutralizing material according to claim 1, which is salt (dNact'''C). (3) The neutralizing material according to claim 1 or 2, wherein the binder is cement. .