Process for production of red phosphorous powder

A process for the production of a red phosphorus powder by the thermal conversion of yellow phosphorus, which comprises heating the yellow phosphorus with refluxing at the boiling point thereof in the presence of a dispersant thereby to convert the yellow phosphorus to red phosphorus until a desired conversion ratio, removing most of the unconverted yellow phosphorus by distillation at the boiling point of yellow phosphorus, and then heating the residue to a temperature not lower than the boiling point of yellow phosphorus thereby to remove the unconverted yellow phosphorus still remaining;

• wherein the dispersant is a member selected from the group consisting of a surfactant, a sparingly soluble in water, finely powdered inorganic compound having an average particle size of 1 .mu.m or less, an inorganic ammonium salt, and an organic compound containing an amino group;
• and wherein the thermal conversion reaction proceeds in the presence of from 0.01 to 5% by weight of the dispersant based on the amount of the yellow phosphorus.