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A method for preparing urea ammonium nitrate solution by utilizing waste nitric acid for stripping tin from circuit boards

A technology of urea ammonium nitrate and ammonium nitrate solution, which is applied in ammonium nitrate fertilizer, urea compound fertilizer, ammonium nitrate and other directions, can solve the problems of narrow sales range, low nitrogen content, and difficulty in large-scale promotion and application of ammonium nitrate concentrate , to achieve the effect of process safety

Active Publication Date: 2019-04-30
SHENZHEN SHENTOU ENVIRONMENT TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, ammonium nitrate concentrate is a non-standard product with low nitrogen content and narrow sales range. Compound fertilizer manufacturers are not very willing to use it.
More critically, ammonium nitrate concentrate is easy to make ammonium nitrate solid by further evaporation and concentration; and ammonium nitrate (solid) has been included in the civil explosives strictly controlled by the country in the "Civil Explosives List", production and use is strictly limited
Combining the above two points, the large-scale popularization and application of ammonium nitrate concentrate is extremely difficult

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] First, place a 2-liter beaker in a constant temperature water bath at 50°C, add 100 ml of clean water as a base, and insert a pH meter below the liquid level; then, use a 1-liter measuring cylinder to hold the tin stripping waste nitric acid A and 20% ammonia water respectively. 1 liter, respectively connect the tin stripping waste nitric acid A and ammonia water to the beaker through two peristaltic pumps and hoses. Turn on the stirring, then turn on the peristaltic pump, inject the tin stripping waste nitric acid A and ammonia water into the clear water at the same time for neutralization and precipitation reaction; fix the tin stripping waste nitric acid A flow rate at 25 ml / min, adjust the ammonia water flow rate to ensure the pH value of the reaction solution Between 4.0 and 4.5. After 1 liter of tin stripping waste nitric acid A has been added, stop adding ammoniacal liquor (439 milliliters of ammoniacal liquor is consumed at this moment); Reactant suction filtrat...

Embodiment 2

[0033] First, place a 2-liter three-neck flask in a constant temperature water bath at 90°C, add 100 ml of ammonium nitrate solution with a concentration of 20% as a base, and insert a pH meter below the liquid level; after that, use 1-liter measuring cylinders to hold tin stripping 1 liter each of waste nitric acid B and 25% ammonia water, and the tin stripping waste nitric acid B and ammonia water were respectively connected to the beaker through two peristaltic pumps and hoses. Turn on the stirring, then turn on the peristaltic pump, inject the tin stripping waste nitric acid B and ammonia water into the clear water at the same time for neutralization and precipitation reaction; fix the tin stripping waste nitric acid B flow rate at 20 ml / min, adjust the ammonia water flow rate to ensure the pH value of the reaction solution Between 4.5 and 5.0. After 1 liter of tin stripping waste nitric acid B has been added, stop adding ammoniacal liquor (467 milliliters of ammoniacal li...

Embodiment 3

[0038] First, 1m of tap water at 70°C 3 Added to a volume of 5m 3 Reactor I, open the industrial online pH meter and stirring paddle respectively, and then start the tin stripping waste nitric acid and ammonia water feed pump, inject the tin stripping waste nitric acid C and 25% ammonia water into the reactor I at the same time to carry out the neutralization and precipitation reaction; Fix the flow rate of tin stripping waste nitric acid C to 1m 3 / hour, adjust the flow of ammonia water to ensure that the pH value of the reaction solution is 4.5 to 5.0; when 2m 3 After the tin stripping waste nitric acid C feeding is completed, close the tin stripping waste nitric acid and ammonia water feed pump (consumption of ammonia water 1.03m 3 ), press filter the reaction materials to obtain 3770 kg (3.7m 3 ), and 680 kilograms of tin hydroxide filter residue. Next, add the primary filtrate to a volume of 5m 3 In the reaction kettle II, start stirring, add 16.5 kilograms of reduc...

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Abstract

The invention relates to a method for preparing urea ammonium nitrate solution by using waste nitric acid for stripping tin from circuit boards, which comprises the following steps: carrying out neutralization precipitation reaction with waste nitric acid for stripping tin and ammonia water by acid-base neutralization method, and filtering to obtain tin-containing filter mud and primary filtrate; process primary filtrate with copper-iron replacement method, reclaim most of the copper ions in the form of copper powder, filter to obtain iron-containing coarse copper powder and secondary filtrate; process secondary filtrate with Fenton method, and then add Adjust the pH value of the secondary filtrate to 5.5-6.0 with ammonia water, filter to obtain iron-containing sludge and the tertiary filtrate; process the tertiary filtrate with heavy metal scavenger precipitation method to remove heavy metal impurities, filter to obtain heavy metal sludge and ammonium nitrate solution; Measure the concentration of ammonium nitrate solution, add urea and liquid fertilizer corrosion inhibitor, configure urea-ammonium nitrate dilute solution; evaporate and concentrate the urea-ammonium nitrate dilute solution to obtain urea ammonium nitrate solution product. The invention can effectively realize the complete resource utilization of tin, copper and nitrate nitrogen in waste nitric acid containing tin stripping.

Description

Technical field: [0001] The invention belongs to the technical field intersecting environmental protection and fertilizer production, and relates to a method for preparing urea ammonium nitrate solution by using waste nitric acid for stripping tin from circuit boards, that is, for preparing urea ammonium nitrate solution that meets the standard of "urea ammonium nitrate solution" (NY2670-2015) Method for the production of urea ammonium nitrate solution. Background technique: [0002] Although the large-scale application of liquid fertilizer in my country started late, it has developed rapidly in recent years due to its advantages such as low production cost, fast fertilizer efficiency, high fertilizer utilization rate, suitable for water and fertilizer integration, and outstanding environmental benefits. Among them, urea ammonium nitrate solution (Urea Ammonium Nitrate solution, referred to as UAN) has become the largest liquid fertilizer product in my country. [0003] UAN...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01C1/18C05G1/00C02F9/10C02F101/20C02F101/22C02F101/30
CPCC01C1/185C02F9/00C05B7/00C02F2001/007C02F2101/163C02F2101/20C02F2101/203C02F2101/22C02F2101/30C02F1/66C02F1/725C02F1/001C02F1/04C02F2301/08C05C1/00C05C9/00C05G5/23
Inventor 王卫红武建刚毛朝霖廖春华陈昌铭黄宽伟黄雪强
Owner SHENZHEN SHENTOU ENVIRONMENT TECH CO LTD