I.　Process　Introduction:　

First　calcine　magnesite,　then　pulverize　to　prepare　magnesium　oxide　powder.　Make　magnesium　oxide　powder　react　with　ammonium　salt　solution,　produce　magnesium　solution　and　volatilize　ammonia.　After　purifying　magnesium　solution,　react　with　carbonated　aqueous　ammonia　or　ammonium　carbonate　solution,　control　certain　process　conditions,　produce　basic　magnesium　carbonate　precipitation,　then　produce　heavy　magnesium　carbonate　powder　with　extremely　good　dispersion　property　and　flowability　through　dehydrating,　washing,　drying　and　packaging.　The　product　is　in　conformity　with　the　standard　of　2010　Pharmacopoeia　of　the　People is　Republic　of　China.　

It　is　also　feasible　to　directly　deliver　the　produced　basic　magnesium　carbonate　wet　cake　into　calcination　system,　and　produce　medical　grade　magnesium　oxide　through　calcination,　pulverizing　and　packaging.　

Magnesium　carbonate　mother　liquid　contains　ammonium　salt　with　certain　concentration,　which　can　be　recycled　to　decompose　magnesite;　

Recycle　the　ammonia　volatilized　through　reaction　between　magnesium　oxide　and　ammonium　salt　to　produce　ammonia　water;　

　A　good　deal　of　CO2　gas　generated　from　magnesium　oxide　calcination　process　reacts　with　the　collected　ammonia　water　to　produce　ammonium　carbonate　solution,　and　recycle　to　precipitate　basic　magnesium　carbonate.

II.　Technical　Advancement:　

Magnesium　conversion　rate　is　above　80%.　Product　quality　is　in　conformity　with　the　standard　of　2010　Pharmacopoeia　of　the　People is　Republic　of　China.　Ammonia　is　recycled,　having　low　production　cost　and　significant　benefits.　CO2　is　recovered,　not　only　reducing　production　cost,　but　also　eliminating　environmental　pollution.

III.　Market　Prospect:　

Medical　magnesium　carbonate　is　mainly　used　in　medicine　for　curing　stomach　illness　and　duodenal　ulcer,　having　relatively　strong　neutralizing　gastric　acid　effect,　and　slow　and　lasting,　which　is　used　to　protect　ulcer　surface;　it　can　also　be　used　to　prepare　artificial　kidney　dialysate,　detoxicated　water　and　other　raw　material　medicine.　In　addition,　it　is　widely　applied　in　articles　of　everyday　use,　cosmetics,　toothpaste,　food　addictive,　flour　ameliorant,　feed,　fire-proof　material,　fire　retardant　and　other　fields.　

Medical　magnesium　oxide　is　mainly　used　in　medicine　industry　as　medicine　for　manufacturing　neutralizing　gastric　acid.　Effect　of　neutralizing　gastric　acid　is　relatively　strong,　slow　and　lasting,　carbon　dioxide　will　not　generate.　After　neutralizing,　generate　magnesium　chloride,　which　may　cause　laxation,　so　it　is　suitable　for　the　patients　with　constipation,　and　gastric　and　duodenum　ulcers　patients　with　excessive　gastric　acid.　In　addition,　it　can　also　be　used　in　manufacturing　ceramics,　enamel,　glass,　dye,　phenolic　aldehyde　plastics　and　other　industries.

IV.　Main　Economic　and　Technological　Indicators:　

Production　of　1t　medical　(food)　grade　magnesium　carbonate　requires　magnesite　(MgO　content　45%)　1.2t;　coal　1.5t;　electricity　750kw·h;　and　water15m3.　Comprehensive　production　cost　is　about　2,500　Yuan/t　(including　tax).　

Market　price　of　the　product　is　7,000　Yuan/t.

V.　Environmental　Protection:　No　effluent,　exhaust　gas,　waste　residue　discharge.　Mother　liquid　and　ammonia　can　be　recycled,　causing　no　disadvantageous　impact　on　the　environment.

VI.　Form　of　Cooperation　and　Service　Method:　

Technical　transfer.　Taking　responsibility　for　process　flow　design,　supporting　equipment　of　standard　equipment,　non-standard　equipment　manufacture　design,　equipment is　plane　layout　design,　equipment　installation　design,　pipe　network　design,　equipment　installation　guidance,　equipment　commissioning,　production　commissioning,　training　for　production　engineers,　analysis　staff　and　technicians,　process　operation　specifications,　raw　material　and　product　analysis　method,　and　preparation　of　intermediate　control　analysis　method;　ensuring　output,　yield　and　quality　to　reach　the　standard;　and　undertaking　turn-key　projects.