FOB Reference Price : $760.00 /ton
Synonyms : Caustic soda lye, caustic LyeSodium hydrate soda lye,White Causticsodium hydroxide, solid solid,Caustic Soda flakes, Sodium hydroxide perlen,Caustic soda,ionic exchange membrane solid,Sodium hydroxide,flake,Caustic soda, liquid,Sodium hydroxide,liquid,Flake caustic,CAUSTIC SODA SOLID,Caustic Soda Pearls
Recommended use: Elution stripping of gold adsorbed onto activated carbon
Other uses :Caustic soda (sodium hydroxide) is a versatile alkali. Caustic soda is an essential ingredient in an array of industrial applications. Its main uses are in the manufacture of pulp and paper, alumina, soap and detergents, petroleum products and chemical production.
In gold processing, strongly alkaline conditions are needed in the stripping of loaded carbon with cyanide solution. This is because caustic soda provides protective alkalinity that stabilizes the cyanide complex and prevents formation of hydrogen sulphide during its use. This stage involves treating the carbon with a caustic-cyanide solution at high temperature (115°C) and pressure (230 kPa). The sodium cyanide is required for solubilising the adsorbed gold cyanide complex and the caustic (sodium hydroxide) is added to maintain a high pH to minimise the evolution of HCN gas.
Elution stripping of gold adsorbed onto activated carbon- Elution involves feeding the carbon into a special pressure vessel called a column. The carbon is pumped to the column and the water is drained. A mixture of caustic soda and cyanide is pumped through the column to contact the carbon. This mixture extracts the gold from the carbon to make a concentrated solution of gold. These parameters are the temperature, the flow rate of the elution, the pH (or the free caustic soda strength).
The advantage of using caustic soda lies in its purity which ensures that not much ‘junk’ material is introduced into the system when correcting the pH. Consistency in specification of the product also ensures process predictability .
Method of Application
Several methods are used to strip loaded activated carbon of gold. These include Alcohol Stripping, Pressurized or Artmospheric Zadra Stripping and the Micron Elution Procedure.
In these processes, gold that is adsorbed on the carbon is desorbed by reversal of the adsorption reaction. The gold, now back in solution is then recovered on wire-wool in electrowinning cells. The solution used to strip the carbon normally contains 1% sodium hydroxide and 0.1% sodium cyanide solution. Variable parameters used in the various stripping technologies include stripping temperatures and pressures as well as the solution concentrations being used.
Molecular Formula: :NaOH
Cas Number: 1310-73-2
Appearance: White, othogonal crystals
Form: Colorless to white ... solid (flakes, beads, granular form).
Boiling point: 1,388 °C
Melting/freezing point: 318 °C
Specific gravity: 2.13 @. 20°C
Flash point: Non-flammable
pH: 12.7 (1% aqueous solution)
1- TRANSPORT INFORMATION
2- STORAGE & HANDLING
Store in a cool, dry, well ventilated place and out of direct sunlight. Store away from foodstuffs. Store away from incompatible materials . Keep containers closed when not in use - check regularly for spills.
25kg PE/PP bags
25kg PE/PP bags (Pallets)
4. Environmental impact
- Although caustic is only slightly toxic to aquatic organisms, a large discharge can change the pH of the aquatic system which may be toxic to aquatic organisms.
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