Arsenic Recovery from Solid Waste via Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional methods for producing high-purity metallic arsenic from arsenic-containing solid waste are complicated and costly due to the difficulty in separating arsenic from impurities like antimony and selenium, requiring repeated purification steps and resulting in arsenic products with low purity.
Innovation Solution
A method involving oxidative alkaline leaching followed by the addition of a mixed ammonium magnesium reagent with carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and hydrophobic macromolecular organic matter to regulate complex arsenate crystallization, allowing for deep separation of arsenic from impurities through high-precision mineralized crystallization and reduction roasting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional fire roasting method is used to recover white arsenic from arsenic-containing solid waste, then arsenic recovery is achieved, but impurity components such as antimony and selenium are inevitably contained in the white arsenic products requiring repeated purification
Solution Approach 1:
The patent applies preliminary action by adding carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and hydrophobic macromolecular organic matter with periodic geometric structure to the alkaline leaching solution before crystallization. These additives pre-regulate the crystallization environment to enable deep separation of arsenic from impurities like antimony and selenium, preventing impurity incorporation into the complex arsenate crystals from the outset.
Solution Approach 2:
The patent uses carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and hydrophobic macromolecular organic matter as intermediaries to regulate the crystallization process. These substances act as mediators between the arsenic-containing solution and the forming crystals, controlling crystal growth to achieve high-purity complex arsenate with arsenic content ≥99.5% by preventing impurity adsorption and cladding during crystallization.
2Manufacturing precision
If repeated purification steps are used to remove impurities from white arsenic products, then arsenic purity is improved, but the flow process becomes complicated and operation difficulty increases
Solution Approach 1:
The patent performs preliminary regulation of the crystallization process by adding specific organic matters to the alkaline leaching solution before crystallization occurs. This preliminary action ensures that complex arsenate crystals form with high purity (≥99.5% arsenic) and minimal impurity content, eliminating the need for repeated purification steps and simplifying the overall process flow.
Solution Approach 2:
The patent changes the crystallization parameters by introducing carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and hydrophobic macromolecular organic matter with periodic geometric structure. These parameter changes regulate the crystallization process to achieve deep separation of arsenic from impurities in a single step, reducing process complexity while maintaining high purity.
3Quantity of substance
If conventional complex arsenate crystallization is used to separate arsenic from impurities, then some separation is achieved, but a small amount of impurity ions are still doped in complex arsenate crystals through adsorption or cladding
Solution Approach 1:
The patent introduces carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and hydrophobic macromolecular organic matter as intermediary substances that regulate the crystallization process. These intermediaries prevent impurity ions from being adsorbed or cladded onto the complex arsenate crystal surfaces, enabling deep separation and producing high-purity crystals with arsenic content ≥99.5%.
Solution Approach 2:
The patent changes the crystallization parameters by adding specific organic matters that regulate crystal growth. This parameter change transforms the conventional crystallization process into a high-precision process that achieves deep separation of arsenic from impurity ions, preventing impurity doping and producing high-purity complex arsenate.
4Manufacturing precision
If multiple sublimation distillation with hydrogen reduction is used to prepare high-purity arsenic from arsenic trioxide, then high-purity arsenic is achieved, but the operation becomes very complicated
Solution Approach 1:
The patent applies preliminary action by regulating the complex arsenate crystallization process with carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and hydrophobic macromolecular organic matter before reduction roasting. This preliminary regulation ensures that the complex arsenate precursor has high purity (≥99.5% arsenic), which simplifies subsequent reduction steps and eliminates the need for multiple sublimation distillation operations.
Solution Approach 2:
The patent changes the crystallization parameters to produce high-purity complex arsenate that can be directly reduced to high-purity metallic arsenic. This parameter change simplifies the overall process by eliminating multiple sublimation distillation steps, reducing operation complexity while maintaining high purity through controlled crystallization followed by single-step reduction roasting.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the process, achieves high-purity metallic arsenic with a purity of not lower than 99.5%, reduces impurity doping, and facilitates industrial production with high efficiency and low costs.
Implementation Method 1
regulating and controlling the mineralized crystallization process of complex arsenate through high-precision organic-inorganic interface matching synergistic effect generated by a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and a hydrophobic macromolecular organic matter having a periodic geometric structure
Implementation Method 2
a small amount of impurity ions can still be doped in complex arsenate crystals in a manner of adsorption or cladding
Implementation Method 3
performing oxidative alkaline leaching on nonferrous metallurgy arsenic-containing solid waste to obtain an arsenic-containing alkaline leaching solution
Implementation Method 4
performing oxidative alkaline leaching on nonferrous metallurgy arsenic-containing solid waste
Implementation Method 5
roasting the complex arsenate crystals cladded with an organic matter, then mixing the roasted complex arsenate crystals cladded with the organic matter with carbon powder, performing reduction roasting
Implementation Method 6
recycling metallic arsenic from smoke through condensation
Data Source
AI summary
A method for preparing high-purity metallic arsenic from arsenic-containing solid waste through a short flow process is provided. The method includes: performing oxidative alkaline leaching on nonferrous metallurgy arsenic-containing solid waste to obtain an arsenic-containing alkaline leaching solution; sequentially adding a mixed ammonium magnesium reagent consisting of a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter, a magnesium compound and an ammonium compound, and a hydrophobic macromolecular organic matter having a periodic geometric structure into the arsenic-containing alkaline leaching solution, and taking a reaction under stirring to obtain complex arsenate crystals cladded with an organic matter; and roasting the complex arsenate crystals cladded with the organic matter, then mixing the roasted complex arsenate crystals cladded with the organic matter with carbon powder, performing reduction roasting, and recycling metallic arsenic from smoke through condensation.