阅读说明：本技术 在盐穴中采用氨碱法生产纯碱过程中得到的废料的储存 (Storage of waste obtained in the production of soda ash by the ammonia-soda process in salt caverns ) 是由 塞伊兰·伊斯梅尔 阿卡尔·凯米立 塞伊兰·优素福 拉提夫·喀亚汗·穆罕穆德 埃米尔·阿德南 于 2020-03-05 设计创作，主要内容包括：本发明涉及将氨碱法生产过程中作为燃料的煤产生的灰烬废弃物和从该生产过程中获得的蒸馏废弃物的排放与储存在废弃的盐穴(10)中。在废弃的盐穴(10)中,氨碱法生产纯碱过程中产生的废料和原材料煤的废料被储存在容积与盐水体积相等的空间中。因此,消除了可能对环境造成损害的废料,并且使废料罐的成本降到最低,并提供了解决固体废料(80)储存问题的方法,固体废料(80)储存是氨碱法最重要的成本支出之一。(The invention relates to the discharge and storage of ash waste from coal as fuel in an ammonia-soda process and distillation waste obtained from the process in a waste salt cavern (10). In the waste salt cavern (10), the waste generated in the process of producing soda ash by an ammonia-soda process and the waste of raw material coal are stored in a space with the volume equal to that of brine. Thus, waste materials that may be environmentally damaging are eliminated and the cost of the canister is minimized and a solution to the problem of solid waste (80) storage, which is one of the most important cost expenditures for the ammonia-soda process, is provided.)

1. A method for storing waste material generated in the ammonia-soda process for producing soda ash in a waste salt cavern (10), wherein the method comprises:

i, discharging saturated salt water in the waste salt cavern (10) with the help of a pump or an air compressor, and sending the saturated salt water to a factory for use;

ii, removing the designed tubing present in said abandoned salt cavern (10) and removing the wellhead assembly from the casing (11) joint;

iii, transporting waste (80) and ash of coal used in the soda production process from a waste pond to the area of the abandoned salt cavern (10) by using a truck, wherein the waste (80) and the ash are stored in a storage bin (50);

iv, feeding the waste materials (80) in the storage bin (50) into a conical tank (60) with a mixer through a conveying belt (51), and then mixing the waste materials (80);

and v, conveying the waste subjected to fluidization and homogenization treatment to a salt pit (10) from a pipeline through a pump (61).

2. The method of claim 1, wherein the waste material and the coal ash are stored in the waste salt caverns (10).

3. The method of claim 1, wherein the storage capacity of the waste material is 800.000m³To 140.000m³In the meantime.

4. The method of claim 1, wherein pipes are removed, step pumps are lowered and brine is discharged in the depleted salt cavern (10).

Technical Field

The invention relates to the storage of waste material obtained in the production of soda ash by the ammonia-soda process (Solvay process) in waste salt pits.

Background

If underground leaching exploitation method is adopted to prepare and produce soda ash (Na can be used)₂CO₃Expressed) required brine, the service life of the cavern is 4-5 years, depending on the thickness of the salt bed and the design of the cavern.

When all the brine is taken out of the salt cavern, impurities (Ca) in the salt layer and the main layer²⁺、Mg²⁺Si, etc.) collects at the bottom of the salt cavern. The solid impurities accumulated at the bottom of the salt cavern account for 5 to 30 percent of the total volume of the salt cavern. The amount of solid impurities varies with the salinity of the rock salt layer and the thickness of the intermediate impurity layer.

From the literature, there are two methods for the production of brine in the ammonia-soda process:

a. leaching mining;

b. the solid salt is dissolved in a tank or pond.

If the underground rock salt mine is close to the alkali plant (0-40km), the most economical and environmentally friendly method is to obtain saturated brine by underground leaching exploitation. In the method, drilling is carried out up to the bottom of the salt formation. Gluing the sleeve and providing a seal. According to the engineering requirement, two movable pipes are adopted to form a cave to produce saturated brine. In the process of forming the cave, vegetable oil or inert gas (N) is adopted₂) As an isolating material. The salt layer is dissolved by injecting water into the cavern. Impurities (Ca, Mg, Si, etc.) of the salt layer and the intermediate layer are precipitated on the cavern base during the dissolution process. Saturated brine is taken from the upper part of the cavern, wherein the saturated brine can be called clean water. The clean water is sent to a factory for obtaining brine.

The process flow is completed within 4-5 years from the beginning of salt production in the salt cavern. At the completion of the process, the bottom of the cavern had solid impurities (5% -30%) and the upper region of the cavern had saturated brine.

In the process of producing one ton of soda ash by adopting ammonia-soda process, the obtained distillation waste slurry is between 8 and 10 tons. The slurry directly enters a wastewater tank and is dried, then passes through a settler, and the liquid part of the slurry is separated out and enters the wastewater tank as denser slurry; or the dense slurry is passed through a filter to form a drier slurry that is fed to a lagoon.

Therefore, the storage of the waste obtained during the production of soda ash by the ammonia-soda process, as well as the process for rendering the above-mentioned waste environmentally harmless, impose a large load on the low cost aspect expected from the use of the ammonia-soda process. The invention relates to a more economical and more environment-friendly method for storing waste materials obtained in the process of producing soda ash by an ammonia-soda process. Detailed information related to the present invention is given below.

Disclosure of Invention

The present invention relates to the storage of the waste obtained during the production of soda ash by the ammonia-soda process in abandoned salt caverns, in order to eliminate the above mentioned drawbacks and bring new advantages to the related art.

The main object of the present invention is to provide a storage of distillation waste generated during the production of soda.

It is another object of the present invention to provide for the storage of waste coal ash generated during soda ash production.

It is another object of the invention to provide the use of the waste salt caverns.

In order to achieve the above objects and those that will be evident from the detailed description given below, the present invention relates to the storage of waste material generated during the ammonia-soda process. Accordingly, the waste material is stored in a waste salt cavern. Therefore, the waste material obtained in the process of producing the soda ash by the ammonia-soda process is stored, so that the method is harmless to the environment.

The invention relates to a method for storing waste materials obtained in the process of producing sodium carbonate by an ammonia-soda process in a waste salt pit, which is characterized by comprising the following process steps:

i, discharging the saturated salt water in the waste salt cavern with the help of a pump or an air compressor, and sending the salt water to a factory for use;

ii, removing specially designed tubing present in the abandoned cavity and removing the wellhead assembly from the casing joint;

iii, transporting waste obtained in the process of producing the calcined soda by the ammonia-soda process and ash of used coal to an area where a waste salt cavern is located from a waste pool by using a truck;

iv, storing the waste transported from the waste pool in a bin, transporting the waste from the bin into a conical tank with a mixer through a transport belt, mixing and fluidizing the waste, and then mixing the waste;

and v, conveying the waste subjected to fluidization and homogenization treatment to a salt cavern from a pipeline through a specially designed pump.

The process waste mentioned in the present invention is distillation waste and coal ash.

In another preferred embodiment of the invention, the storage capacity of the waste material may be 800.000m³To 1400.000m³In the meantime.

In a preferred embodiment of the invention, in a waste cavern, the piping is removed, the step pump is lowered, and brine is drained.

Drawings

FIG. 1 is a representative schematic of a rejected salt cavern.

FIG. 2 is a representative schematic of a cavern with saturated brine drained.

FIG. 3 is a schematic diagram of the filling of caverns with waste produced by the ammonia-soda process.

List of reference numerals:

10 salt cavern

11 casing tube

12 cavity top zone

13 bottom area of cavity

20 ground floor

30 salt layer

40 ground layer clay

50 stock bin

51 material conveying belt

60 conical tank

61 Pump

70 saturated brine inlet

80 solid waste

Detailed Description

In the following detailed description, the present invention relates to the storage of the waste material obtained in the soda production process by the ammonia-soda process in the waste salt caverns 10 and is explained with reference to examples, which are only intended to make the understanding of the invention easier and are not intended to be limiting in any way.

In the prior art, 8 to 10 tons of distilled waste slurry can be obtained in the process of producing one ton of soda ash by adopting an ammonia-soda process. The mud directly enters a wastewater tank and is dried, then the liquid part of the mud passes through a settler, and the denser mud enters the wastewater tank; or the dense slurry is passed through a filter press to form a drier slurry that is fed to a wastewater basin. Even in the most dense slurries, the humidity is between 35% and 40%. The water in the mud can dissolve 11 to 12 percent of CaCl₂And 4% to 5% NaCl.

Brine is one of important raw material inputs in the process of producing soda ash by an ammonia-soda process, and one method for obtaining brine is an underground salt leaching exploitation method. The life of such a structure, called a salt cavern 10, which can also be defined as obtaining brine, is 4-5 years, calculated on the basis of the annual salt usage. After the brine extraction is complete, the bottom 13 of the cavern remains contaminated with impurities and some process contaminants.

The main object of the present invention relates to the discharge and storage of the waste ash of coal as fuel in the ammonia-soda process and distillation waste obtained in the process into the waste salt caverns 10. In the waste salt cavern 10, distillation waste obtained in the process of producing soda ash by the ammonia-soda process and waste of its raw material coal are stored in a hollow portion having a volume equal to that of brine. In this way, the waste 80, which may be harmful to the environment, is removed, and in addition, the cost of the canister can be minimized, and the storage problem of the waste 80, which is one of the most important costs in the ammonia-soda process, can be solved.

According to the following calculation:

in the process of producing one ton of soda ash by adopting an ammonia-soda process, the weight of steam is about 3-3.5 tons, the pressure is between 40 and 50 bars, and the temperature is between 430 and 450 ℃. This steam is generated in natural gas-fueled or coal-fueled boilers.

In the case of steam generation using coal as a fuel, lignite having a reference calorific value of 4000kcal/g is used in an amount of 0.6 to 0.8 ton per one ton of soda ash produced, wherein the ash is present in an amount of about 25 to 30% by weight.

The ash produced by the steam boiler per ton of soda produced is as follows:

0.8 ton coal x 0.3 weight percent ash yield 0.24 ton ash;

about 60% of this ash is fly ash, 40% is bottom ash;

0.24 ton ash x 0.6 ton fly ash (0.144 ton fly ash);

0.24 ton ash x 0.4 weight percent bottom ash is 0.096 ton bottom ash.

Depending on the quality of the fly ash, it is possible to use fly ash in cement plants. The bottom ash is mainly stored in the waste area. If the quality of the fly ash is not high, the fly ash is mixed with bottom ash and stored in a waste area. The ash mainly contains impurities such as Ca, Mg, Si, etc. in its structure.

As an example, soda ash is produced at a rate of 400.000 tons/year, roughly calculated as follows:

(400.000 ton/year) × (1.6 ton NaCl/ton Na₂CO₃) 640.000 tons/year of NaCl were required. If the salt is produced from underground rock salt, and if 75% rock salt is used, and its density is 2.1g/cm³：

640.000/(0.75×2.1)＝406.000m³The amount of dissolved rock salt per year,

406.000×0.25×1.4＝142.000m³per year, 40% moisture mud accumulates at the bottom of the cavern.

406.000–142.000＝264.000m³In one year, saline water still remained in the caverns.

When the service life of the cave is set to be 5 years;

264.000×5＝1320.000m³the brine stays in the cavern.

The brine was removed and replaced with distilled waste mud and coal ash (bottom ash + fly ash).

Amount of waste sludge: 400.000 t/year × 0.5 t/year × 5 year 1000.000 ton

Density 1.6g/cm³

The amount of the waste mud is 1000.000/1.6-625.000 m³5 years old

Total ash content of coal-containing boiler ((0.144+0.096) × (400.000 t/year) × (5 years))/2 g/cm³＝240.000m³5 years old

Total waste volume of 625.000+240.000 of 865.000m³5 years old

The volume of the formed cave is 1320.000m³And 5, carrying out the year.

Accordingly, the amount of waste material generated in the process of producing soda ash by the ammonia-soda process is 865.000m³In 5 years, the cavity amount of the cave after the brine discharge is 1320.000m³And 5, carrying out the year. All waste material 80 produced until the end of 5 years may be stored in the system of caverns 10. Furthermore, the ash and distillation waste 80 placed in the salt cavern 10 for storage is then covered, their connection to the environment being broken.

The invention is carried out in two basic steps. In a first step, all the salt present in the salt cavern is taken from the cavern, and then in a second step, the gap formed by the removal of the salt is filled with waste material.

The invention relates to the storage of waste material produced in the production of soda ash by the ammonia-soda process in a waste salt cavern 10, wherein the following process steps are adopted:

i, discharging the saturated salt water in the waste salt cavern 10 with the help of a pump or an air compressor, and sending the saturated salt water to a factory for use;

ii, removing specially designed tubing present in the abandoned cavity 10 and removing the wellhead assembly from the casing 11 junction;

iii, transporting the waste 80 obtained in the process of producing the calcined soda by the ammonia-soda process and the ash of the used coal from the waste pool to the area of the waste salt cavern 10 by using a truck, and storing the waste and the ash in the storage bin 50;

iv, feeding the determined volume of the waste 80 in the bin 50 into the conical tank 60 with a mixer through the conveyor belt 51, and then mixing the waste;

v, transporting the waste material after fluidization and homogenization from the pipeline to the salt cavern 10 by a specially designed pump 61.

Before step i is performed, as shown in fig. 1, the salt caverns comprise a cavern input section arranged on the ground layer 20; a cemented casing 11 connected to the input above the salt cavern and below the surface layer 20; the upper salt cavern portion 12 below the salt layer 30; the waste is collected in the lower part of the salt cavity 13.

The process in step i is applied to a salt cavern 10, as shown in fig. 2, which is converted to an empty cavern, which does not contain salt in its upper part 12.

Distillation waste and coal ash from production facilities used in the ammonia-soda process are first stored in a silo 50.

The waste material stored in the silo 50 is transferred to the conical tank 60 by means of the conveyor belt 51 to be applied in step iv. In order to transport the solid waste 80 to the salt cavern, the solid waste 80 should have a consistency. To render the solid waste 80 fluid, 20 to 30% by weight of brine 70 is added to the waste 80 in the conical tank 60.

In step iv of the present invention, the mixing process applied to the brine and the waste material provided in conical tank 60 lasts for a period of at least 1 day.

After step v of applying the present invention, the salt cavern 10 is as shown in fig. 3. After step v, the deposited solid waste material 80 displaces the salt present at the upper portion 12 of the salt cavern.

Therefore, in the case of producing soda ash by the ammonia-soda process, the storage capacity problem and the chemical pollution problem of the distilled waste sludge and the ash of the coal-fired boiler in the storage factory can be solved in the cavern 10 for producing brine by the underground rock salt deposit leaching exploitation method according to the method.

Due to the present invention, in the waste salt cavern 10, distillation waste generated in the soda production process by the ammonia-soda process and waste of coal as a raw material are stored in a space having a volume equal to that of brine. Thus, the waste 80, which may be environmentally damaging, can be eliminated, the cost of the canister can be minimized, and the problem of storing the waste 80, which is one of the most important cost expenditures for the ammonia-soda process, can be addressed.

The scope of protection of the invention is not limited to the illustrative disclosures described above. Since similar embodiments will be obvious to a person skilled in the relevant art from the above disclosure, without departing from the main principle of the invention.