JP2005152869A - Manufacturing method of obtaining waste water treating agent for mine and the like while recycling slaked lime - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the conventional method of directly adding slaked lime or calcium carbonate to objective waste water to be treated containing heavy metal converts the slaked lime itself and others into a massive quantity of lime cake waste commingled with the heavy metal therein, moreover, the lime cake waste can not be utilized and recycled. <P>SOLUTION: A saturated calcium hydroxide solution prepared by adding slaked lime and calcium carbonate, or slaked lime obtained by reacting lime cake-calcined quick lime with water to river water etc., agitating the mixture and subjecting the mixture to solid-liquid separation is used as a treating agent for flocculating and settling the heavy metals in mine waste water and the like. On the other hand, slaked lime-lime cake on the separated solid side is added to river water again, thereby, the saturated calcium hydroxide solution is newly prepared and, as a result, the waste water treating agent for mine etc., can be produced without making the resources wasteful by recycling slaked lime. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention adds slaked lime, calcium carbonate, or slaked lime obtained by reacting lime cake calcined quicklime with water to river water, etc., and stirs it, and a saturated calcium hydroxide solution obtained by solid-liquid separation is used for heavy metals such as mine wastewater. Slaked lime lime cake on one separated solid side can be re-added to river water etc. to make a new saturated calcium hydroxide solution and obtained while reusing slaked lime It belongs to the technical field of wastewater treatment agents.

Until now, slaked lime and calcium carbonate were directly added to the wastewater to be treated, so the slaked lime itself was disposable and wasted resources.

The method of directly adding slaked lime or calcium carbonate to the wastewater to be treated containing heavy metals has been wasting resources because the slaked lime itself is made into a large amount of lime cake waste mixed with heavy metals. Moreover, the lime cake waste could not be recycled because there was no usage.
The present invention is to provide a method for solving the above problems.

In order to achieve the object, the present invention provides a saturated calcium hydroxide solution obtained by adding and stirring slaked lime, calcium carbonate, or slaked lime obtained by reacting lime cake calcined quicklime and water to river water and the like, followed by solid-liquid separation. Is a treatment agent for agglomerating and precipitating heavy metals such as mine wastewater, and one of the separated solid slaked lime cake can be added to river water again to make a saturated calcium hydroxide solution. The purpose is achieved because wastewater treatment agents such as mines can be produced without wasting resources by recycling slaked lime.

The effect of the present invention is that slaked lime etc. is not directly added to waste water containing heavy metals, but slaked lime etc. is added to clean water such as river water to separate saturated calcium hydroxide solution, which is used as a treatment agent for mine waste water etc. The mixed lime cake is not discarded, and the precipitate aggregated by the saturated calcium hydroxide solution is obtained as a heavy metal resource because a large amount of lime is not mixed. Also, the slaked lime lime cake separated from the saturated calcium hydroxide solution can be reused repeatedly because it does not contain heavy metals, and has an epoch-making effect.

Embodiments of the present invention will be described based on examples.

River water and the like 1 is once collected in the tank 2 and mixed with slaked lime, calcium carbonate 3 and the like 3 while checking the state within a pH range of 13 while stirring. Further, the mixture is sent to a dehydrator 4 such as a filter cloth dewatering or the like while continuing stirring, and separated into solid and liquid. The liquid becomes a saturated calcium hydroxide solution, and becomes the treating agent 6 for coagulating and precipitating heavy metals such as mine wastewater. When it is insufficient due to dissolution, slaked lime, calcium carbonate 3 or the like is appropriately added. This is an example.

Since the processing of mine wastewater etc. continues continuously for 24 hours, the waste does not stop as well. The amount of lime cake waste such as mine wastewater has been enormous, and no good measures have been taken to secure the disposal site or to examine the recycling method.
However, the advantage of the present invention is that slaked lime, calcium carbonate, or slaked lime obtained by reacting lime cake calcined quicklime and water is added to river water and the like, and the saturated calcium hydroxide solution obtained by solid-liquid separation is used for mine wastewater. It can be used as a treatment agent for agglomerating and precipitating heavy metals such as slaked lime lime cake on one solid side by adding it again to river water, etc., so that a new saturated calcium hydroxide solution can be made and reused slaked lime In this way, wastewater treatment agents such as mines can be repeatedly manufactured without wasting resources, so that there is industrial applicability as one of the countermeasures for environmental problems and waste problems.

It is a manufacturing process diagram to obtain a wastewater treatment agent such as a mine while reusing slaked lime

Explanation of symbols

1 Nearest river water, etc. 2 Mixing tank (with a stirrer) for manufacturing treatment agents such as mine wastewater
3 Slaked lime, calcium carbonate, or lime cake calcined lime slaked lime slaked lime and water 4 Dehydrater such as filter cloth dewatering and centrifugation 5 Slaked lime lime cake (reuse)
6 Mine wastewater treatment agent (saturated calcium hydroxide solution) pH approx. 13

Claims (2)

Slaked lime, calcium carbonate, or slaked lime obtained by reacting lime cake calcined quicklime with water is added to river water, etc., and stirred, and the saturated calcium hydroxide solution obtained by solid-liquid separation is used to agglomerate and precipitate heavy metals such as mine wastewater. The manufacturing method which makes it the processing agent for making it. The lime cake such as slaked lime on one solid side separated in solid-liquid according to claim 1 can be reused as a material for making a saturated calcium hydroxide solution by adding it again to river water etc. Is a method for producing a treatment agent for repeatedly aggregating and precipitating heavy metals such as mine wastewater without wasting resources by adding slaked lime, calcium carbonate, or slaked lime obtained by reacting lime cake calcined quicklime with water.

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