Dithiocarbamic Acid Depressants for Selective Copper Iron Sulfide Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current froth flotation mineral separation practices face health, safety, and environmental concerns due to the use of toxic reagents like Sodium hydrosulfide (NaHS) and other depressants, which are inefficient and non-selective, particularly in separating copper and iron sulfides from molybdenite ores.
Innovation Solution
The use of dithiocarbamic acids or salts with specific functional groups as depressants in froth flotation processes, which selectively depress copper and iron sulfides without requiring additional reagents, enhancing mineral recovery efficiency and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Sodium hydrosulfide (NaHS) and traditional depressants are used for mineral separation, then mineral separation can be achieved, but health, safety, and environmental concerns arise due to toxicity and hydrogen sulfide formation
Solution Approach 1:
The patent replaces toxic traditional depressants (NaHS, ferrocyanides, Nokes reagent) with dithiocarbamic acid derivatives that form a protective gel layer on mineral surfaces. This gel layer mechanism converts the harmful chemical toxicity issue into a beneficial physical barrier mechanism, achieving effective mineral depression without hydrogen sulfide formation or toxic residue, thus resolving the contradiction between separation effectiveness and safety/environmental concerns
Solution Approach 2:
The invention changes the chemical parameters of the depressant system by using dithiocarbamic acid derivatives with specific molecular structures (containing -NH-C(=S)-S- groups). These structural parameter changes enable the formation of gel layers on mineral surfaces, fundamentally altering the depression mechanism from chemical toxicity-based to physical gel-layer-based, thereby eliminating harmful effects while maintaining separation effectiveness
2Reliability
If traditional depressants are used, then mineral separation is achieved, but selectivity between different sulfide minerals is poor
Solution Approach 1:
The patent applies local quality by using dithiocarbamic acid derivatives that selectively interact with specific mineral surface sites. The gel layer formation occurs locally on target mineral surfaces (such as chalcopyrite) while leaving other minerals (such as molybdenite) unaffected. This localized selective depression achieves high selectivity between different sulfide minerals, resolving the contradiction between effective separation and mineral selectivity
3Reliability
If multiple reagents are used to achieve selective depression, then separation performance improves, but process complexity increases
Solution Approach 1:
The invention applies universality by using dithiocarbamic acid derivatives as a single multi-functional reagent that simultaneously provides depression, selectivity, and gel layer protection. This single reagent system replaces multiple traditional reagents (depressants, modifiers, pH controllers), simplifying the process while maintaining or improving separation performance through the versatile gel layer mechanism
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
The dithiocarbamic acids or salts effectively increase the concentration of target minerals in the froth, achieving high selectivity and efficiency in mineral separation while reducing the need for toxic chemicals, thus improving health and safety standards and environmental impact.
Implementation Method 1
The depressant selectively decreases the affinity of some minerals to the froth such that they remain depressed in the bulk pulp
Implementation Method 2
Froth flotation relies on hydrophobicity differences between valuable minerals and waste gangue to achieve their separation
Data Source
AI summary
A process for recovering a first mineral comprising the steps of: (a) providing a pulp comprising solids and water, wherein the solids comprise the first mineral; (b) adding a first depressant to the pulp; (c) subjecting the pulp to a froth flotation process to produce a froth comprising the first mineral; and (d) recovering the froth; characterized in that the first mineral is a sulfide mineral, and the first depressant consists of one or more dithiocarbamic acids or salts thereof of formula (I). A composition comprising the first depressant, and further comprising one, two or three of a collector, a second depressant and a mineral. The use of a dithiocarbamic acid or salt thereof of formula (I). The dithiocarbamic acid or salt thereof of formula (I) which is 3-ammo-l,2-propanediol dithiocarbamic acid or a salt thereof, 2-amino-2-methyl-l, 3, -propanediol dithiocarbamic acid or a salt thereof, or N- phenylethylenediamine dithiocarbamic acid or a salt thereof.