A resource treatment method for emergency disposal of waste aluminum ash

Abstract

The present invention provides a resource treatment method for emergency disposal of waste aluminum ash, including: stirring and mixing magnesium phosphate, sodium acetate and water to obtain an elimination agent; mixing the elimination agent with the waste aluminum ash in a ratio of 2-3:20 by mass for 20-40 minutes to obtain a base material for removing water-reactive property; after static treatment, mixing with auxiliary materials and pressing into solid concrete bricks; the overall process design of the present invention is reasonable, effectively removing the water-reactive property of the waste aluminum ash by using the elimination agent, quickly converting ammonia into ammonium ions, and solidifying into relatively stable aluminum hydroxide and magnesium ammonium phosphate, avoiding a large amount of ammonia overflowing and polluting the environment; moreover, the method of the present invention is easy to operate, can safely dispose of the aluminum ash in illegal disposal events in a short period, reduce environmental risk hazards, and has good economic and social benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste treatment, and particularly relates to a resource treatment method for emergency disposal of waste aluminum ash. Background Art

[0002] Aluminum ash slag is the waste residue generated in the aluminum industry production process, which is divided into primary aluminum ash slag and secondary aluminum ash slag. Its environmental hazard characteristic is reactivity, and some also have leaching toxicity or release flammable gases when encountering water, with relatively high environmental risks. Therefore, aluminum ash slag is clearly defined as hazardous waste.

[0003] Since aluminum ash slag will react with water to release oxygen and is also prone to spontaneous combustion when damp, enterprises need to declare and register the generated hazardous substances such as aluminum ash and properly dispose of them in accordance with the relevant requirements of hazardous waste management to ensure environmental safety when disposing of aluminum ash slag.

[0004] However, in reality, there are still illegal disposal incidents of aluminum ash slag. Due to the strong reaction characteristics of aluminum ash itself, fire and secondary environmental pollution problems may be triggered at any time. Therefore, there is an urgent need for a method to deal with the aftermath of aluminum ash in illegal disposal incidents. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides a resource treatment method for emergency disposal of waste aluminum ash.

[0006] The technical solution of the present invention is as follows: A resource treatment method for emergency disposal of waste aluminum ash, comprising:

[0007] S1. Eliminate the water reactivity of waste aluminum ash

[0008] S1-1. Preparation of elimination agent

[0009] Mix magnesium phosphate, sodium acetate and water by stirring to obtain an elimination agent;

[0010] S1-2. Remove the water reactivity of waste aluminum ash

[0011] Mix the elimination agent and waste aluminum ash in a mass ratio of 2-3:20 for 20-40 min to obtain a base material with removed water reactivity;

[0012] The chemical reaction equation for removing water reactivity is:

[0013] Mg 3 (PO 4 ) 2 +2H + =3Mg 2+ +2HPO 4 2- ;

[0014] AlN+3H2 O=Al(OH) 3 +NH 3 ↑;

[0015] NH 3 +H + =NH 4 + 、NH 3 +H 2 O=NH 3 ·H 2 O;

[0016] Mg 2+ +NH 4 + +HPO 4 2- +6H 2 O=MgNH 4 PO 4 ·6H 2 O+H + ;

[0017] Mg 2+ +HPO4 2－ +NH 3 ·H 2 O=NH 4 MgPO 4 ↓+H 2 O;

[0018] S2, Resource utilization

[0019] S2-1, Static treatment of the base material

[0020] Perform static treatment on the base material after removing the water reactivity;

[0021] S2-2, Preparation of concrete solid bricks

[0022] Mix the base material after static treatment with the auxiliary material in a mass percentage ratio of 90 - 95%: 5 - 10%, and then use a brick press to press them into concrete solid bricks.

[0023] Furthermore, the specific step S1-1 is: Stir and mix 26 - 30 parts of magnesium phosphate, 5 - 11 parts of sodium acetate and 50 - 80 parts of water by mass for 15 - 30 minutes to obtain the elimination agent.

[0024] Note: The waste aluminum ash reacts quickly with the elimination agent in the above ratio to generate relatively stable magnesium ammonium phosphate, avoiding a large amount of ammonia gas overflowing and polluting the environment, and basically eliminating the water reactivity of the waste aluminum ash.

[0025] Furthermore, the step S1-2 is carried out in a sealed device.

[0026] Note: Ammonia will still be produced due to the reaction during mixing. In order to prevent ammonia from leaking out due to subsequent reactions, it must be carried out in a sealed device.

[0027] Furthermore, the static treatment time in step S2-1 is 24 to 36 hours.

[0028] Note: Static treatment can effectively ensure that the chemical reaction is sufficient and complete before entering the brick-making process; it can effectively avoid the dangerous factors caused by the reaction of unreacted waste aluminum ash and water in the subsequent brick-making process due to insufficient reaction.

[0029] Furthermore, the auxiliary materials in step S2-2 include 70-85% of silicate cement and 15-30% of curing agent in terms of mass percentage.

[0030] Furthermore, the auxiliary materials in step S2-2 include 50-55% of silicate cement, 35-40% of construction waste and 5-15% of curing agent in terms of mass percentage.

[0031] Description: Solid concrete bricks can be quickly produced by using silicate cement, construction waste, curing agent and materials after removing water reactivity, thereby effectively realizing waste resource utilization.

[0032] Furthermore, the curing agent is water-based epoxy resin.

[0033] Description: Water-based epoxy resin has better environmental performance and meets environmental protection requirements; in addition, it has extremely high adhesion and high hardness after curing, so it is more suitable for the preparation of solid bricks.

[0034] Furthermore, the size of the concrete solid brick in step S2-2 is 230mm*115mm*50mm.

[0035] Note: The size specifications of concrete solid bricks should actually take into account the subsequent market demand. Therefore, the size specifications should be selectively adjusted according to market demand.

[0036] Furthermore, the concrete solid brick is applied for municipal use.

[0037] Note: Since the prepared concrete solid bricks are affected by their own strength, they are preferably used for municipal purposes and should be avoided as much as possible in residential construction projects.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: The overall process design of the present invention is reasonable. The water-reactivity of waste aluminum ash is effectively removed by using an elimination agent, ammonia is rapidly converted into ammonium ions, and solidified into relatively stable aluminum hydroxide and magnesium ammonium phosphate, avoiding a large amount of ammonia overflow and environmental pollution. Moreover, the method of the present invention is easy to operate, can safely dispose of the aluminum ash in illegal disposal incidents in a short period, reduce potential environmental risks, and has good economic and social benefits. Specific Embodiments

[0039] Example 1

[0040] A resource treatment method for emergency disposal of waste aluminum ash includes:

[0041] S1. Eliminate the water-reactivity of waste aluminum ash

[0042] S1-1. Preparation of the elimination agent

[0043] Mix 26 parts of magnesium phosphate, 5 parts of sodium acetate and 50 parts of water by mass and stir for 15 minutes to obtain the elimination agent;

[0044] S1-2. Remove the water-reactivity of waste aluminum ash

[0045] In a sealed device, mix the elimination agent and waste aluminum ash in a mass ratio of 2:20 in the sealed device for 20 minutes to obtain the base material with removed water-reactivity;

[0046] The chemical reaction equation for removing water-reactivity is:

[0047] Mg 3 (PO 4 ) 2 +2H + =3Mg 2+ +2HPO 4 2- ;

[0048] AlN+3H 2 O=Al(OH) 3 +NH 3 ↑;

[0049] NH 3 +H + =NH 4 + 、NH 3 +H 2 O=NH 3 ·H 2 O;

[0050] Mg 2+ +NH 4 ++HPO 4 2- +6H 2 O=MgNH 4 PO 4 ·6H 2 O+H + ;

[0051] Mg 2+ +HPO4 2－ +NH 3 ·H 2 O=NH 4 MgPO 4 ↓+H 2 O;

[0052] S2. Resource utilization

[0053] S2-1. Static treatment of the base material

[0054] The base material with water-reactive substances removed is subjected to static treatment for 24 h;

[0055] S2-2. Preparation of concrete solid bricks

[0056] The static-treated base material and the auxiliary material are mixed in a mass percentage ratio of 90%:10% and then pressed into concrete solid bricks using a brick press. Among them, the auxiliary material includes 70% portland cement and 30% curing agent by mass percentage; the curing agent uses water-based epoxy resin; the size specification of the concrete solid brick is 230 mm * 115 mm * 50 mm.

[0057] Example 2

[0058] A resource treatment method for emergency disposal of waste aluminum ash, including:

[0059] S1. Elimination of water-reactive property of waste aluminum ash

[0060] S1-1. Preparation of elimination agent

[0061] 28 parts of magnesium phosphate, 8 parts of sodium acetate and 60 parts of water are stirred and mixed for 20 min according to mass parts to obtain the elimination agent;

[0062] S1-2. Removal of water-reactive property of waste aluminum ash

[0063] In a sealed device, the elimination agent and the waste aluminum ash are mixed in a mass ratio of 2.5:20 in the sealed device for 30 min to obtain the base material with water-reactive property removed;

[0064] The chemical reaction equation for removing water-reactive property is:

[0065] Mg 3 (PO4 ) 2 + 2H + = 3Mg 2+ + 2HPO 4 2- ;

[0066] AlN + 3H 2 O = Al(OH) 3 + NH 3 ↑;

[0067] NH 3 + H + = NH 4 + 、NH 3 + H 2 O = NH 3 ·H 2 O;

[0068] Mg 2+ + NH 4 + + HPO 4 2- + 6H 2 O = MgNH 4 PO 4 ·6H 2 O + H + ;

[0069] Mg 2+ + HPO4 2－ + NH 3 ·H 2 O = NH 4 MgPO 4 ↓ + H 2 O;

[0070] S2, Resource utilization

[0071] S2-1, Static treatment of the base material

[0072] The base material with water-reactive substances removed is subjected to static treatment for 30 h;

[0073] S2-2, Preparation of concrete solid bricks

[0074] The static-treated base material and the auxiliary material are mixed in a mass percentage ratio of 92%:8% and then pressed into concrete solid bricks by a brick press. Among them, the auxiliary material includes 80% portland cement and 20% curing agent by mass percentage; the curing agent is water-based epoxy resin; the size specification of the concrete solid brick is 230 mm * 115 mm * 50 mm.

[0075] Example 3

[0076] A resource treatment method for emergency disposal of waste aluminum ash, comprising:

[0077] S1. Eliminate the water-reactivity of waste aluminum ash

[0078] S1-1. Preparation of elimination agent

[0079] Mix 30 parts of magnesium phosphate, 11 parts of sodium acetate and 80 parts of water by mass and stir for 30 min to obtain the elimination agent;

[0080] S1-2. Remove the water-reactivity of waste aluminum ash

[0081] In a sealed device, mix the elimination agent and waste aluminum ash in a mass ratio of 3:20 in the sealed device for 40 min to obtain a base material with removed water-reactivity;

[0082] The chemical reaction equation for removing water-reactivity is:

[0083] Mg 3 (PO 4 ) 2 +2H + =3Mg 2+ +2HPO 4 2- ;

[0084] AlN+3H 2 O=Al(OH) 3 +NH 3 ↑;

[0085] NH 3 +H + =NH 4 + 、NH 3 +H 2 O=NH 3 ·H 2 O;

[0086] Mg 2+ +NH 4 + +HPO 4 2- +6H 2 O=MgNH 4 PO 4 ·6H 2 O+H + ;

[0087] Mg 2+ +HPO4 2－ +NH 3 ·H 2 O=NH 4MgPO 4 ↓ + H 2 O;

[0088] S2. Resource utilization

[0089] S2-1. Static treatment of the base material

[0090] The base material with water-reactive substances removed is subjected to static treatment for 36 h;

[0091] S2-2. Preparation of concrete solid bricks

[0092] The static-treated base material and the auxiliary material are mixed in a mass percentage ratio of 95%:5% and then pressed into concrete solid bricks by a brick press. Among them, the auxiliary material includes 85% portland cement and 15% curing agent by mass percentage; the curing agent uses water-based epoxy resin; the size specification of the concrete solid brick is 230 mm * 115 mm * 50 mm.

[0093] Example 4

[0094] The difference from Example 1 is that: the auxiliary material described in step S2-2 includes 50% portland cement, 35% construction waste, and 15% curing agent by mass percentage; the curing agent uses water-based epoxy resin.

[0095] Example 5

[0096] The difference from Example 2 is that: the auxiliary material described in step S2-2 includes 55% portland cement, 35% construction waste, and 10% curing agent by mass percentage; the curing agent uses water-based epoxy resin.

[0097] Example 6

[0098] The difference from Example 3 is that: the auxiliary material described in step S2-2 includes 55% portland cement, 40% construction waste, and 5% curing agent by mass percentage; the curing agent uses water-based epoxy resin.

[0099] Application example

[0100] Resource-based on-site treatment of waste aluminum ash in an illegal temporary storage warehouse of a foundry in Guangzhou:

[0101] After measurement, the stacked volume of aluminum ash in the foundry is 3625.20 cubic meters, and the test result of the density by the core cutter method is 0.97 g / cm³. By measurement and calculation, the mass of waste aluminum ash m = ρV = 3625.20 × 0.97 = 3516.44 tons;

[0102] 100 samples were collected on site (sample numbers B20111721-GF01 to B20111721-GF40, B20111821-GF01 to B20111821-GF60). Subsequently, 8 of the samples were tested for composition. According to the "Identification Standard for Hazardous Wastes - Identification of Leaching Toxicity" (GB5085.3-2007) and "Identification Standard for Hazardous Wastes - Identification of Reactivity" (GB5085.5-2007), all 100 samples were tested for water reactivity and inorganic fluoride (excluding calcium fluoride) leaching toxicity. The composition test results are shown in Table 1;

[0103] Table 1: List of test results of waste aluminum ash composition

[0104]

[0105]

[0106]

[0107] The resource recovery treatment method of Example 1 of the present invention is used in combination with the resource recovery emergency treatment equipment in the prior art to recover the above-mentioned waste aluminum ash. The emergency treatment equipment is specifically shown in Table 2; the processing capacity is 8 tons of waste aluminum ash / hour, working 12 hours a day, about 100 tons of waste aluminum ash / day; the total construction period is expected to be about 30 days;

[0108] Table 2: List of resource emergency disposal equipment

[0109]

[0110] Among them: 1) In order to reduce the dust of the feed, a spiral feeder is used to transfer the aluminum ash to the feed hopper; 2) Dosing system: the reagent is stored in a 30-cubic-meter storage tank outside the factory. The reagent enters the plastic barrel (one for backup and one for use) in the factory from the storage tank through a pipeline, and then sprays into the sealed mixer through a nozzle to react with the waste aluminum ash; 3) Under the push of the mixer blades, the reacted aluminum ash is transferred out of the mixer and then discharged through the conveyor belt; 4) The concrete solid bricks are packaged with a baler and put into storage, and the outbound delivery is arranged according to the subsequent market sales situation.

[0111] For the solid concrete bricks obtained after the above resource treatment, the dimensions, appearance quality, strength grade, carbonation coefficient, and softening coefficient of the sample bricks were tested in accordance with the requirements of "Solid Concrete Bricks" (GB / T 21144-2007). The inspection report (No. JW22QC030061) shows that the sample bricks meet the requirements of "Solid Concrete Bricks" (GB / T 21144-2007) and can be used as finished bricks; according to the test report (No. HJ220401-02) issued by Guangzhou Zhongke Testing Technology Service Co., Ltd., the components of the sample bricks are shown in Table 3;

[0112] Table 3: List of Test Results of Sample Brick Components

[0113]

[0114]

[0115] As can be seen from Table 3, the main components of the sample bricks are alumina, magnesia, silicate, etc. Compared with the waste aluminum ash, the aluminum nitride component decreased from 6%-10% to 3%.

Claims

1. A resource treatment method for emergency disposal of waste aluminum ash, characterized in that, it includes: S1. Eliminate the water-reactive property of waste aluminum ash S1-1. Preparation of elimination agent Mix magnesium phosphate, sodium acetate and water by stirring to obtain the elimination agent; S1-2. Remove the water-reactive property of waste aluminum ash Mix the elimination agent and waste aluminum ash in a ratio of 2-3:20 by mass for 20-40 min to obtain the base material with the water-reactive property removed; The chemical reaction equation for removing the water-reactive property is: Mg 3 (PO 4 ) 2 +2H + =3Mg 2+ +2HPO 4 2- ; AlN + 3H 2 O = Al(OH) 3 + NH 3 ↑; NH 3 +H + =NH 4 + 、NH 3 +H 2 O=NH 3 ·H 2 O; Mg 2+ +NH 4 + +HPO 4 2- +6H 2 O=MgNH 4 PO 4 ·6H 2 O+H + ; Mg 2+ + HPO4 2－ + NH 3 ·H 2 O = NH 4 MgPO 4 ↓ + H 2 O; S2. Resource utilization S2-1. Static treatment of the base material Conduct static treatment on the base material with the water-reactive property removed; S2-2. Preparation of concrete solid bricks Mix the static-treated base material and auxiliary materials in a ratio of 90-95%:5-10% by mass percentage and use a brick press to press them into concrete solid bricks; The specific step S1-1 is: Mix 26-30 parts of magnesium phosphate, 5-11 parts of sodium acetate and 50-80 parts of water by mass for 15-30 min to obtain the elimination agent; The step S1-2 is carried out in a sealed device; The static treatment time in step S2-1 is 24-36 h; The auxiliary materials in step S2-2 include 70-85% of portland cement and 15-30% of curing agent by mass percentage; The auxiliary materials in step S2-2 include 50-55% of portland cement, 35-40% of construction waste and 5-15% of curing agent by mass percentage; The curing agent uses water-based epoxy resin; The size specification of the concrete solid bricks in step S2-2 is 230mm*115mm*50mm.

2. The resource treatment method for emergency disposal of waste aluminum ash according to claim 1, characterized in that, apply the concrete solid bricks to municipal construction.

Images