Process to produce magnesium compounds, and various by-products using sulfuric acid in a hcl recovery loop

2:

• The process of claim 1, further comprising the step (g) of thermally decomposing the magnesium sulfate in sulphur dioxide gaz and magnesium oxide.

3:

• The process of claim 1, wherein the magnesium-bearing ores are magnesium silicate ores or tailings.

4:

• The process of claim 3, wherein the magnesium silicate ores are serpentine mineral, lizardite, antigorite, olivine, talc, sepiolite or a mixture thereof.

5-7. (canceled)

8:

• The process of claim 1, wherein the neutralizing agent is serpentine tailing.

9:

• The process of claim 1, further comprising adding an oxidizing agent to convert the iron in solution in a bivalent form to a trivalent form.

10:

• The process of claim 9, wherein the oxidizing agent is chlorine gas, hydrogen peroxide, potassium permanganate, dioxygen, air, or a mixture thereof.

11:

• The process of claim 1, wherein the neutralization step (e) is conducted at a temperature between 60-110° C.

12:

• The process of claim 1, wherein the base is magnesium oxide, sodium hydroxide, potassium hydroxide or a mixture thereof.

13-14. (canceled)

15:

• The process of claim 1, further comprising the step (e′) of precipitating the contained manganese from the neutralized brine.

16:

• The process of claim 15, further comprising adding an oxidative agent to convert the manganese in solution from a bivalent form to a quatrivalent form.

17:

• The process of claim 16, wherein said oxidative agent is chlorine gas, hydrogen peroxide, potassium permanganate, dioxygen, air, or a mixture thereof.

18-19. (canceled)

20:

• The process of claim 1, further comprises the step (e″) of precipitating by crystallization the magnesium chloride contained in the enriched magnesium chloride brine using dry gaseous hydrogen chloride obtaining a crystal of magnesium chloride and a solution of magnesium chloride and filtrating to separate said crystal of magnesium chloride from said solution of magnesium chloride, the filtrated magnesium chloride crystal being added to sulfuric acid to form magnesium sulfate and hydrocloric acid which is recycled.

21:

• The process of claim 20, wherein the dry gaseous hydrogen chloride is sparged or bubbled through the enriched magnesium chloride brine.

(canceled)

23:

• The process of claim 1, wherein hydrochloric acid mixed with the magnesium sulfate is stripped of by the use of a gas producing gaseous and wet hydrochloric acid, the gaseous hydrochloric acid being recycled.

(canceled)

25:

• The process of 20, wherein the wet hydrochloric acid and the filtrated magnesium chloride solution are further dehydrated in a dehydration unit in contact with a concentrated hydrochloric acid solution producing dry gaseous hydrochloric acid which is recycled and a diluted hydrochloric solution which is reused in the leaching step (a).

26:

• The process of claim 20, further comprising the step (f′) of converting the magnesium chloride contained in the enriched magnesium chloride brine into magnesium metal by electrolysis.

28:

• The process of claim 27, further comprising the step (e′) of precipitating the contained manganese from the neutralized brine.

29:

• The process of claim 27, further comprising the step (g) of thermally decomposing the magnesium sulfate in sulphur dioxide gaz and magnesium oxide.