Production of calcined ceramic pigments
AssigneeKeeling & Walker Limited
InventorsHarry Augustus Morriss, John Peter Hugh Williamson
Life of this patent
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Abstract
The process for producing zirconium based pigments (also known as stains) comprises the direct use of plasma disassociated zirconium sand. The sand is comminuted to a suitable particle size, mixed with a color determining agent such as ammonium metavanadate and a mineralizer such as sodium fluoride, after which the resulting mixture is calcined to bring about a reaction between the zirconium sand and the color determining agent to produce the required pigments. The resulting calcined pigment is then ground to a suitable particle size ready for application to ceramic tiles.
Claims22
In the process for the production of a zircon based stain by reacting a zirconia containing material with a color determining agent the improvement comprising the steps of:
- a. plasma dissociating a zircon sand to obtain a plasma-dissociated zircon sand having zirconia rich phase, a silica rich phase and no more than 30% unreacted zircon sand;
- 2.
comminuting said plasma dissociated zircon sand without prior leaching to obtain a comminuted plasma dissociated zircon sand containing at least 90% by weight of its original silica content before comminution;
- and
- 3. reacting said comminuted plasma dissociated zircon sand with a color
- determing agent. 2. In the process for the production of a zircon based stain by reacting a zirconia containing material with a color determining agent the improvement comprising the steps of:
- 1. plasma dissociating a zircon sand to obtain a plasma dissociated zircon sand having a zirconia rich phase, a silica rich phase and no more than 30% unreacted zircon sand;
- 2. comminuting said plasma dissociated zircon sand without prior leaching to obtain a comminuted plasma dissociated sand containing at least 90% by weight of its original silica content before comminution, by milling;
- 3. mixing said comminuted zircon sand with a color determining agent and a mineralizer in the absence of any silica other than that contained in said comminuted zircon sand;
- and
- 4. reacting said mixture comminuted zircon sand with said color determing agent and said mineralizer.
In the process for the production of a zircon based stain by reacting a zirconia containing material with a color determining agent the improvement comprising the steps of:
- 1. plasma dissociating a zircon sand to obtain a plasma dissociated zircon sand having a zirconia rich phase, a silica rich phase and no more than 30% unreacted zircon sand;
- 2. comminuting said plasma dissociated zircon sand by wet milling and drying without prior leaching to obtain a comminuted plasma dissociated zircon sand containing at least 90% by weight of its original silica content before comminution, said wet milling being effected in the presence of water and a silica attacking agent which attacks only the surface of the silica leaving most of the silica in its chemical condition prior to comminution;
- and
- 3. reacting said comminuted zircon sand with a color determing agent.
Dependencies are inferred from the claim text.