1. A sulfate process for producing titania from a titaniferous material which includes the steps of:
(a) leaching the titaniferous material with a leach solution containing sulfuric acid and forming a leach liquor that includes an acidic solution of titanyl sulfate (TiOSO4) and iron sulfate (FeSO4);
(b) separating the leach liquor and a residual solid phase from the leach step (a);
(c) separating titanyl sulfate from the leach liquor from step (b) and using at least part of the leach liquor remaining after separation of the titanyl sulphate as part of the leach solution in one of the leach step (a) or a further leach step;
(d) hydrolysing the separated titanyl sulfate and forming a solid phase containing hydrated titanium oxides;
(e) separating the solid phase containing hydrated titanium oxides and a liquid phase that are produced in the hydrolysis step (d); and
(f) calcining the solid phase from step (e) and forming titania;
(g) a further leach step of leaching the residual solid phase from step (b) with a leach solution containing sulfuric acid and forming a leach liquor that includes an acidic solution of titanyl sulfate and iron sulfate and a residual solid phase;
(h) separating the leach liquor and the residual solid phase from step (g); and
(i) supplying the separated leach liquor to the leach step (a) andor mixing the separated leach liquor with the leach liquor from step (b).
2. The process defined in claim 1 further comprising carrying out the leach step (a) and the further leach step (g) in the same vessel.
3. The process defined in claim 2 further comprising returning the residual solid phase from step (b) to the vessel, wherein the residual solid phase forms part of the titaniferous material subjected to leaching in the leach step (a).
4. The process defined in claim 1 further comprising carrying out the leach step (a) and the further leach step (g) in a separate vessel or vessels.
5. The process defined in claim 4 wherein the further leach step (g) includes supplying the residual solid phase from step (b) to the vessel or vessels.
6. The process defined in claim 1 wherein the leach step (a) andor the further leach step includes selecting andor controlling the leach conditions in the leach step or steps to avoid undesirable amounts of premature hydrolysis of hydrated titanium oxides and undesirable amounts of premature precipitation of titanyl sulfate.
7. The process defined in claim 6 wherein the leach conditions include any one or more than one of acid concentration, leach temperature and leach time.
8. The process defined in claim 6 further comprising selecting andor controlling the acid concentration to be at least 350 gl sulfuric acid throughout the leach step (a) andor the further leach step (g) when operating at a leach temperature in the range of 95\xb0 C. to the boiling point in order to avoid premature hydrolysis.
9. The process defined in claim 6 further comprising selecting andor controlling the acid concentration at the end of the leach step (a) andor the further leach step (g) to be less than 450 gl when operating at a leach temperature in the range of 95\xb0 C. to the boiling point in order to avoid an undesirable amount of premature precipitation of titanyl sulfate.
10. The process defined in claim 6 further comprising selecting andor controlling the leach conditions so that the titanium ion concentration in the leach liquor is less than 50 gl in the leach liquor at the end of the leach step (a) andor the further leach step (g).
11. The process defined in claim 10 further comprising selecting andor controlling the leach conditions so that the titanium ion concentration in the leach liquor is 40-50 gl in the leach liquor at the end of the leach step (a) andor the further leach step (g).
12. The process defined in claim 1 further comprising carrying out the leach step (a) andor the further leach step (g) in the presence of an additive that accelerates the rate of leaching the titaniferous material.
13. The process defined in claim 12 wherein the additive is selected from a group that includes iron, a titanium (III) salt, a thiosulfate salt, sulfur dioxide, a reduced sulfur containing species, and mixtures thereof.
14. The process defined in claim 1 further comprising carrying out the leach step (a) andor the further leach step (g) in the presence of a reductant that reduces ferric ions to ferrous ions in the acidic solution or solutions of titanyl sulfate and iron sulfate produced in the leach step (a).
15. The process defined in claim 14 wherein the reductant is selected from a group that includes iron, a titanium (III) salt, a thiosulfate salt, sulfur dioxide, a reduced sulfur containing species, and mixtures thereof.
16. The process defined in claim 1 wherein the leach step (a) solubilises at least 50% by weight of the titaniferous material supplied to the leach step.
17. The process defined in claim 1 further comprising the steps of precipitating iron sulfate from the leach liquor from step (b) and separating precipitated iron sulfate from the leach liquor prior to the titanyl sulfate separation step (c).
18. The process defined in claim 1 wherein the titanyl sulfate separation step (c) includes a solvent extraction step of extracting titanyl sulfate from the leach liquor from step (b) into a solvent and thereafter stripping titanyl sulfate from the solvent and forming a solution that contains titanyl sulfate and thereafter hydrolysing the titanyl sulfate-containing solution in the hydrolysis step (d).
19. The process defined in claim 18 further comprising using at least part of a raffinate from the solvent extraction step as at least part of the leach solution in leach step (a) andor in the further leach step (g).
20. The process defined in claim 19 wherein the leach solution in the leach step (a) and the further leach step (g) includes the raffinate and make-up fresh sulfuric acid.
21. The process defined in claim 19 wherein the raffinate from the solvent extraction step has an acid concentration of at least 250 gl sulfuric acid.
22. The process defined in claim 18 wherein the solvent extraction step includes contacting the leach liquor with the solvent which includes a modifier.
23. The process defined in claim 1 further comprising controlling the hydrolysis step (d) to produce a selected particle size distribution of the hydrated titanium oxides product.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An apparatus, comprising:
a display device comprising
a data-holding circuit having a capacitance;
a display portion having a plurality of pixel electrodes;
a first carrier substrate on which the data-holding circuit and the display portion are formed; and
a second carrier substrate that is disposed opposite to the first carrier substrate being placed above the display portion, an opposing substrate being absent above an area in which the data-holding circuit is disposed,
wherein a provider of the capacitance comprises a sense amplifier circuit for amplifying and latching a magnitude of an electric potential between two nodes;
the sense amplifier circuit has a first and second latch circuit;
the display device has
a transmission control portion being provided that allows or disallows signal transmission between one of the two nodes and at least one of the first and second latch circuits; and
the output voltage amplitude of the first latch circuit is less than the output voltage amplitude of the second latch circuit; and
an electroconductive layer disposed around a periphery of the display device, a distance between the data-holding circuit and the electroconductive layer around the periphery of the display device being more than 100 times greater than a thickness of a dielectric body which constitutes the capacitance of the data-holding circuit.
2. The apparatus according to claim 1, wherein a distance between the data-holding circuit and the electro conductive layer around the periphery is more than 1,000 times greater than the thickness of the dielectric body which constitutes the capacitance of the data-holding circuit.
3. The apparatus according to claim 1, comprising:
a dielectric layer being disposed between the display device and an inner wall of the apparatus, the dielectric layer being composed of a low-k material.
4. The apparatus according to claim 1, comprising:
a dielectric layer being disposed between the display device and an inner wall of the apparatus, the dielectric layer being composed of air.