Partial oxidation process with magnetic separation of the ground slag

Abstract

Synthesis gas is produced by the partial oxidation of a feedstock comprising petroleum coke and/or heavy liquid hydrocarbon fuel containing sulfur and having an ash that contains nickel, vanadium and silicon. An iron-containing or an iron and calcium-containing additive is introduced into the reaction zone along with the feed. The additive combines with at least a portion of the iron and nickel constituents and sulfur found in the feedstock to produce a liquid phase washing agent that collects and transports at least a portion of the vanadium-containing oxide laths and spinels and other ash components out the reaction zone. Slag and other particulate matter is separated from the effluent gas stream and ground to produce a heterogeneous mixture of magnetic and non-magnetic solid particles. The particles have various degrees of magnetic susceptibility and are thereby separated into the following three separate portions of magnetic particles: (1) particles of an Fe-Ni alloy, and a minor amount of magnetite particles; (2) particles of an oxysulfide phase of iron and nickel, a minor amount of particles of vanadium compounds, and particles of iron silicate and calcium silicate; and (3) particles of vanadium-containing spinels, and particles of metal silicates. The first and third portions are sent to a metal refiner to recover nickel and vanadium respectively. The second portion of magnetic particles having an increased Fe/V wt. ratio is recycled through the gasifier.