Reagent Flotation

Flotation reagent is the most important thing in a flotation process, in which this reagent is needed for removal of mineral concentrates that will be done. Basically the flotation process depends completely on the adhesion properties of certain minerals to air (hydrophobic), and to water (hydrophilic), and therefore the addition of chemical substances in the form of reagent.

Any one of various chemical substances that govern and regulate most flotation processes. The introduction of flotation reagents into the liquid phase of the pulp and subsequent adsorption along the liquid-gas and solid-liquid interfaces create conditions for the selective flotation of specific mineral particles. There are three principal types of flotation reagents: collectors, regulating agents, and frothing agents.

THESE ARE SOME OF THE FLOTATION REAGENT WHICH CAN BE USED IN THE FLOTATION PROCESS

COLLECTORS	FUNCTION
Xanth (ogen ) ates	Sulfide Flotation
Dithiophosphates	Sulfide Flotation
Carboxylates ( Fatty acids )	Carbonate / Oxide / Sulfide Flotation
Dithiophosphates	Sulfide Flotation
Alkyl ammonium salts	Silicate / Oxide Flotation

FROTHER	FUNCTION
Aliphatic alcohol ( Methyl isobutyl carbinol )	Frother
Cyclic alcohol ( Pine oil, Eucalyptus oil )	Frother, Collector
Aromatic alcohol (Cresols, Xylenol )	Frother

REGULATOR ( Modifiers )	FUNCTION
Lime (Dalkeith)	Sulfide pH - Depressor phyrite
Sodium hydroxide	pH-Disperses gangue
Sulfuric acid	pH
Copper Sulfide	Sphalerite Activation
Sodium Sulfide	Activation /Oxidation
Cyanide	Depressor Sulfide
Chromate	Depressor Galena

  

Reagent used in the flotation process can be classified into:

• Collector

Collectors are organic substances that impart hydrophobicity to mineral particles to be floated, which makes possible the attachment of the particles to gas bubbles. Collector is a material that can cause mineral particles into the air like it, namely by coating the surface of mineral particles with a polar reagent.  

So on the outside of the minerals that make up the chemical reaction occurs non-polar layers are easy to draw the air, and minerals, it easily attaches to air bubbles. The molecules of a collector are generally composed of two parts: 

(1) a hydrocarbon (nonpolar) and carboxyl group and 

(2) an amino-acid group and another (polar) chemically active group affixed to the mineral surface. 

Collectors are classified as nonionogenic and ionogenic according to their ability to dissociate into ions in an aqueous medium. Nonionogenic collectors are virtually insoluble in water and usually include nonpolar, hydrocarbon liquids, such as kerosine and petroleum oils. Ionogenic collectors dissociate in water into an anion and cation and, depending on the type of hydrophobic ion, are divided into anion collectors

Sample collectors for sulfide minerals are Xanthate, and Dithiophosphate. As for non-sulfide minerals Fatty acids are saturated and unsaturated.

• Frother

Frother chemical to use to help stabilize air bubbles that form on the flotation process, so it is not easily broken. Air bubbles that are formed should be able to move freely in the pulp and can take precious mineral particles, and then float into the pulp.

Frothing agents increase the stability of the mineralized froth and facilitate the dispersion of air in the pulp and the formation of the minutest possible bubbles. Such agents are usually organic surfactants, the molecules of which have a polar and nonpolar group and are adsorbed along the surface of the gas-liquid interface, thereby reducing surface tension

Examples of Flotation frother frother is DOWFROTH Series, MIBC, and Polyalkoxyparaffins.

• Modifier (modifying agent)

Modifier is used to return to the original surface properties. The goal is to improve the selectivity in the flotation process. Modifying agent can be grouped into 3 kelompo, namely:

1.   Regulating and Dispersing Agent 
Regulor serves to control the pH, eliminating the influence of slime disruption, colloid, and sea salt. An example is CaO, Na2CO3

Dispersing Agent serves to release the slime on the surface of minerals.
An example is Na2SiO3

2.   Activators

Aims to increase the activity of mineral surfaces in order to interact with the collector, so the collector adsorbs on the particle surface for the better. An example is the Cu + + to float sphalerite, and Ca + + for quartz float.

3.   Depresant
Prevent flotation of certain minerals without blocking other mineral flotation. Used when the float ability unwanted minerals float together with the minerals that will float by certain collectors. An example is the CN-(pyrit, sphalerite), and Zn + + (sphalerite)