I.　Process　introduction

When　using　sulfuric　acid　as　decomposition　agent　to　dispose　boron　and　magnesium　mineral　and　produce　boric　acid,　major　elements　of　mother　liquid　are　MgSO4　and　H3BO3.　Purify　mother　liquid　(or　use　magnesium　sulfate　heptahydrate　as　raw　material　and　conduct　purification　treatment　through　dissolution)　to　obtain　pure　magnesium　solution,　then　use　bicarbonate　as　precipitant,　react　with　the　magnesium　therein　under　certain　concentration　and　temperature　condition　to　generate　basic　magnesium　carbonate　precipitation.　Through　ageing,　rinsing,　dehydrating　and　drying,　produce　medical　(heavy)　magnesium　carbonate.　Magnesium　carbonate　mother　liquid　reacts　with　alkali　to　volatilize　ammonia,　collect　ammonia　water　and　recycle.　

Use　the　produced　magnesium　carbonate　as　precursor　to　control　different　process　conditions,　and　produce　high-purity　magnesium　oxide　through　calcination,　pulverization,　grading　and　packaging.

II.　Technical　Advancement

Boron　yield　is　above　85%,　and　magnesium　conversion　rate　is　over　82%.　The　produced　magnesium　carbonate　is　slightly　fine　spherical　crystal,　having　good　dispersion　property　and　flowability,　which　is　in　conformity　with　American　medical　standard.　Magnesium　oxide　is　in　conformity　with　the　standard　of　Second　Edition　of　2005　Pharmacopoeia　of　the　Peoples　Republic　of　China.　Boric　acid　product　quality　is　in　conformity　with　the　standard　of　product　in　the　same　category　in　Chile.　

　Light　magnesium　carbonate　and　magnesium　oxide　of　all　grades　can　also　be　produced　by　controlling　different　process　conditions.

III.　Market　Prospect

Magnesium　salt　products　represented　by　magnesium　oxide　and　magnesium　carbonate　have　prospecting　international　market　situation,　Chinese　annual　export　volume　accounts　for　about　60%　of　aggregate　production,　belonging　to　the　important　products　earning　foreign　exchange　through　export.　With　the　construction　and　development　of　national　economy,　domestic　medicine,　food,　rubber,　plastics,　electronics,　fire-proof　material,　domestic　chemical　engineering,　ceramics,　metallurgy　and　other　industries　have　growing　demand　for　magnesiumcompound,　and　the　market　demand　is　prosper.　Therefore,　its　market　and　development　prospect　is　very　broad.

IV.　Technical　Sources

Industrialization　technology.　This　process　was　successfully　researched　and　developed　by　our　Research　Institute　in　2003,　and　our　Research　Institute　took　the　lead　to　realize　industrialization　in　Shandong　Hongji　Chemical　Industry　Co.,　Ltd.　and　Zhongyuan　Chemical　Industry　Co.,　Ltd.　in　2005.　It　has　formed　the　annual　production　capacity　of　boric　acid　20,000t,　medicinal　grade　high-purity　magnesium　carbonate　18,000t　and　medicinal　magnesium　oxide　6,000t.　Through　constant　improvement　and　verification　in　the　practice,　this　process　has　become　the　only　domestic　mature　boron　magnesium　comprehensive　utilization　industrialization　technology　that　has　been　successfully　applied　in　industrial　practice.

V.　Product　Quality

Boric　acid　product　quality　is　in　conformity　with　the　standard　of　product　in　the　same　category　in　Chile　or　GB538-2006　prime　grade　product　standard.　Ton　product　profit　is　1,200-1,600　Yuan;　medical　magnesium　carbonate　is　in　conformity　with　the　standard　of　Second　Edition　of　2005　Pharmacopoeia　of　the　Peoples　Republic　of　China.　Ton　product　profit　is　3,600　Yuan;　and　medical　magnesium　oxide　is　in　conformity　with　the　standard　of　Second　Edition　of　2005　Pharmacopoeia　of　the　Peoples　Republic　of　China.

VI.　Investment　Scale

According　to　annual　production　of　high　quality　boric　acid　5,000t　and　co-production　medicinal　(heavy)　magnesium　carbonate　4,000t,　the　required　equipment　investment　is　5　million　Yuan,　including　magnesium　carbonate　investment　2　million　Yuan;　in　case　of　co-production　magnesium　oxide,　equipment　investment　1.5　million　Yuan　should　be　increased.

VII.　Environmental　Protection　

Boric　acid　mother　liquid　is　comprehensively　utilized,　magnesium　carbonate　mother　liquid　is　used　in　ammonia　recovery　without　effluent　discharge.　Boric　sludge　generated　during　process　is　used　in　brick　making　or　compound　fertilizer　manufacturing,　causing　no　disadvantageous　impact　on　environment.

VIII.　Economic　Benefits

High　additional　value,　extremely　big　profit　space　and　significant　economic　benefits.

IX.　Form　of　Cooperation:　

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.