13-02-2013, 02:28 PM
PREPARATION OF POTASH ALUM FROM SCRAP ALUMINIUM
[attachment=50699]
INTRODUCTION
Aluminium because of its low density, high tensile strength and resistance to corrosion is widely used for manufacture of airplane, automobiles, lawn furniture as well as for Aluminium cans. Being good conductors of electricity it is also used for transmission of electricity. Aluminium foil is used for wrapping cigarettes, confectionery etc. Aluminium is also used for making utensils. The recycling of Aluminium cans and other Aluminium products is a very positive contribution to saving our natural resources. Most of the recycled Aluminium is melted and recast into other Aluminium metal products or used in the production of various Aluminium compounds, the most common of which are the alums.
PROCEDURE
1. A small piece of scrap Aluminium is cleaned with steel wool and cut into very small pieces.
2. The small piece of scrap Aluminium or Aluminium foil are but into a conical flask and about 50mlof 4m KOH solution is added to dissolve tke Aluminium.the flask may be heated gently in order to facilitate dissolution.since during this step hydrogen gas is evolved this step is done in well ventilated area.the heating is continue until all of the Aluminium reacts.the solution is filtered to remove any insoluble impurities and the volume is reduced to about 25ml by heating.
3. The filtrate is allowed to cool.6M H2SO4 is added slowly until insoluble Al(OH)3 just forms in the solution.
4. The mixture is heated gently until the Al(OH)3 ppt.dissolves.the resulting solution is cooled in an ice bath for about 30min whereby alum crystals should separate out.
5. The crystals are filtered from the solution and the crystals are washed with 50/50 ethanol water mixture.
6. The mass of alum crystals is determined.Aluminium
[attachment=50699]
INTRODUCTION
Aluminium because of its low density, high tensile strength and resistance to corrosion is widely used for manufacture of airplane, automobiles, lawn furniture as well as for Aluminium cans. Being good conductors of electricity it is also used for transmission of electricity. Aluminium foil is used for wrapping cigarettes, confectionery etc. Aluminium is also used for making utensils. The recycling of Aluminium cans and other Aluminium products is a very positive contribution to saving our natural resources. Most of the recycled Aluminium is melted and recast into other Aluminium metal products or used in the production of various Aluminium compounds, the most common of which are the alums.
PROCEDURE
1. A small piece of scrap Aluminium is cleaned with steel wool and cut into very small pieces.
2. The small piece of scrap Aluminium or Aluminium foil are but into a conical flask and about 50mlof 4m KOH solution is added to dissolve tke Aluminium.the flask may be heated gently in order to facilitate dissolution.since during this step hydrogen gas is evolved this step is done in well ventilated area.the heating is continue until all of the Aluminium reacts.the solution is filtered to remove any insoluble impurities and the volume is reduced to about 25ml by heating.
3. The filtrate is allowed to cool.6M H2SO4 is added slowly until insoluble Al(OH)3 just forms in the solution.
4. The mixture is heated gently until the Al(OH)3 ppt.dissolves.the resulting solution is cooled in an ice bath for about 30min whereby alum crystals should separate out.
5. The crystals are filtered from the solution and the crystals are washed with 50/50 ethanol water mixture.
6. The mass of alum crystals is determined.Aluminium