Silver halide precipitation process with deletion of materials

In a double-jet batch process comprising

• forming a radiation-sensitive silver halide dispersion by reacting a silver salt solution and a halide salt solution within a dispersing medium to achieve silver halide grain nucleation followed by silver halide grain growth, wherein during silver halide grain growth the silver and halide salts are concurrently run into a reaction vessel containing the dispersing medium,
• the improvement comprising, while running the silver and halide salt solutions and during silver halide grain growth,
• withdrawing a portion of the dispersion from the reaction vessel,
• reducing the volume of the withdrawn dispersion by separating a portion of the dispersing medium while retaining the silver halide grains within the remaining withdrawn dispersion, and
• returning the remaining withdrawn dispersion to the reaction vessel.

In a double-jet batch process of preparing a silver halide dispersion in the absence of a hydrophilic colloid peptizer comprising

• forming a dispersion of radiation-sensitive silver halide grains and a soluble salt reaction product by reacting water soluble silver and halide salts within a dispersing medium to achieve silver halide grain nucleation followed by silver halide grain growth, wherein during silver halide grain growth the silver and halide salts are separately introduced as aqueous solutions through first and second jets into a reaction vessel containing the dispersing medium,
• the improvement of protecting the silver halide grains from flocculation comprising, while running the first and second jets and during silver halide grain growth,
• separately introducing into the reaction vessel through a third jet a less than 0.01 molar aqueous halide salt solution,
• withdrawing a portion of the dispersion from the reaction vessel,
• passing the withdrawn portion of the dispersion through an ultrafiltration unit containing a semipermeable membrane, thereby separating a portion of the dispersing medium and soluble salt reaction product from the silver halide grains within the dispersion remaining, and
• returning the remaining withdrawn dispersion to the reaction vessel.

In a double-jet batch process of preparing a photographic silver halide emulsion comprising

• forming a silver halide emulsion by reacting aqueous silver and halide salts within a dispersing medium to achieve silver halide nucleation followed by silver halide grain growth, wherein at least during silver halide grain growth the dispersing medium is present in a reaction vessel, a hydrophilic colloid peptizer is present in the dispersing medium, and the silver and halide salt solutions are concurrently run into the reaction vessel containing the dispersing medium,
• the improvement comprising
• withdrawing a portion of the silver halide emulsion from the reaction vessel during silver halide grain growth,
• passing the withdrawn portion of the silver halide emulsion through an ultrafiltration unit containing a semipermeable membrane to separate a portion of the dispersing medium from the silver halide grains and hydrophilic colloid and thereby reduce the volume of the silver halide emulsion withdrawn, and
• returning the withdrawn emulsion, reduced in volume, to the reaction vessel.