Abstract: Disclosed is a process for the manufacture of a chromium-containing catalyst with a reduced amount of chromium-(VI)-oxide which process comprises the steps: a) preparing a solid particulate chromium-containing oxidic catalyst comprising Cr-(VD-oxide, b) introducing the solid particulate catalyst into a reactor in which the catalyst particles are mixed using process gas and/or mechanical means, c) introducing a reducing agent for chromium-(VI) into the reactor, d) treating the solid particulate catalyst with the reducing agent in the reactor for a time, at a temperature and at a pressure, so that the chromium-(VI) content in the particulate catalyst is considerably reduced by the reducing agent, and e) discharging the solid particulate catalyst comprising a reduced chromium-(VI) content from the reactor. The disclosed process is simple and efficient and allows manufacture of chromium-containing oxidic catalysts with low content of Cr-(VI)-oxide on an industrial scale.

Abstract: Disclosed is a process for the manufacture of a chromium-containing catalyst with a reduced amount of chromium-(VI)-oxide which process comprises the steps: a) preparing a solid particulate chromium-containing oxidic catalyst comprising Cr-(VI)-oxide, b) introducing the solid particulate catalyst into a reactor in which the catalyst particles are mixed using process gas and/or mechanical means, c) introducing a reducing agent for chromium-(VI) into the reactor, d) treating the solid particulate catalyst with the reducing agent in the reactor for a time, at a temperature and at a pressure, so that the chromium-(VI) content in the particulate catalyst is considerably reduced by the reducing agent, and e) discharging the solid particulate catalyst comprising a reduced chromium-(VI) content from the reactor. The disclosed process is simple and efficient and allows manufacture of chromium-containing oxidic catalysts with low content of Cr-(VI)-oxide on an industrial scale.