Abstract: The present invention relates to a process for the recovery of bitumen from an oil sand comprising the following phases in succession: (a) mixing an oil sand with a diluent capable of reducing the viscosity and density of the bitumen contained in said oil sand, obtaining a first mixture (slurry) comprising diluted bitumen; (b) mixing said slurry with a basic aqueous solution (BAS) possibly containing salts to increase its ionic strength, capable of removing said diluted bitumen from said oil sand containing it, obtaining a second mixture (BAS-slurry) which can be separated into (i) a liquid phase comprising said diluted bitumen, a fraction of oil sand free of the bitumen removed and water; (ii) a sediment comprising the remaining fraction of said oil sand free of the bitumen removed, water and residual hydrocarbons which can be eliminated by subsequent washings; (c) separating a liquid phase comprising said diluted bitumen removed, from said BAS-slurry mixture; (d) recovering, from said liquid phase separated

Abstract: The present invention relates to a process for the recovery of bitumen from an oil sand comprising the following phases in succession: (a) mixing an oil sand with a diluent capable of reducing the viscosity and density of the bitumen contained in said oil sand, obtaining a first mixture (slurry) comprising diluted bitumen; (b) mixing said slurry with a basic aqueous solution (BAS) possibly containing salts to increase its ionic strength, capable of removing said diluted bitumen from said oil sand containing it, obtaining a second mixture (BAS-slurry) which can be separated into (i) a liquid phase comprising said diluted bitumen, a fraction of oil sand free of the bitumen removed and water; (ii) a sediment comprising the remaining fraction of said oil sand free of the bitumen removed, water and residual hydrocarbons which can be eliminated by subsequent washings; (c) separating a liquid phase comprising said diluted bitumen removed, from said BAS-slurry mixture; (d) recovering, from said liquid phase separated

Abstract: An oligomer of an aspartic acid is provided having repeating monomeric units of aspartic acid of the formula: ##STR1## and by a first chain unit having formula: ##STR2## and a chain stopper unit A which is: ##STR3## wherein X is an alkali metal, R represents H or an alkyl containing from 1 to 4 carbon atoms and R.sub.1 is H or the group --COOX.