Produksi Kalsium Karbonat dr Batu Kapur

Batu kapur adalah batuan sediment yg sebagian besarnya merupakan CaCO3 dlm berbagai bentuk kristalnya spt calcite dan aragonite. Calcite adalah mineral karbonat dgn bentuk kristal yg paling stabil dr CaCO3. Sementara aragonite adalah bentuk kristal lainnya dr CaCO3 dan memiliki kecenderungan utk berubah ke calcite dlm hitungan jutaan tahun.

Di zaman dahulu, batu kapur digunakan sbg bahan bangunan. Bahkan piramid Giza terbuat seluruhnya dr batu kapur. Sekarang ini, CaCO3-lah yg diambil dr batu kapur utk berbagai keperluan industri dan konsumen. Produk CaCO3 secara garis besar dpt dibagi menjadi dua bagian yaitu Ground CaCO3 (GCC) dan Precipitated CaCO3 (PCC).

Dibandingkan dgn GCC, PCC memiliki rentang ukuran partikel yg sempit dan lbh kecil (20 – 70 nm dgn GCC sekitar 1 mikron), bentuknya lbh regular, dan memiliki kemurnian yg lbh tinggi. Krn kualitasnya ini, kebutuhan industri akan PCC terus meningkat.

Menurut British CaCO3 Federation (BCCF), GCC digunakan di:

  • Adhesive and sealants –> main ingredients for sealants, fillers, and adhesive (up to 80% of the formulation), as well as for the viscosity control
  • Animal and pet feeds –> calcium source and digestion aid
  • Construction –> filler for concrete, asphalt, and roofing materials in construction
  • Environment –> natural alkali source for flue gas desulphurization, de-acidification of forests and rivers, and drinking water treatments. Also for fire suppressant
  • Fertilizers –> as calcium source to stabilize the acidity of soil and providing essential calcium for support of crops. And, also for fillers of the fertilizers
  • Food and households –> as calcium source for dietary calcium supplement and antacid, and chemical binder. It is also used as a mild abrasive
  • Glass and ceramics –> calcium source in the glass and kiln control in ceramics industry
  • Paints and surface coatings –> aid to pigmentation, and help controlling the finish products (matt or gloss)
  • Paper –> to reduce acidity of paper, improve durability of printed materials
  • Plastics –> as fillers (up to 25% volume), to improve rheology, and increasing density
  • Rubbers and elastomers –> for flow control (viscosity and rheology)

Seperti halnya GCC, PCC jg digunakan di industri adhesive and sealants, dan paints and inks. Krn kualitasnya yg lbh bagus, PCC jg digunakan di industri:

  • Food and pharmaceuticals –> as calcium source, mineral base, mild abrasive and viscosity aid for toothpaste. They are mostly used in liquid form where very small size in valuable
  • Paints and inks –> as extenders to increase opacity
  • Papers –> due to its much finer and closely controlled particle size, PCC is used more for paper coating and surface finishing
  • Plastics –> for flow control and reinforcement

Sekarang ini, trend market global spt dirilis oleh analyst dr Global Industry, 66% dr PCC digunakan utk brightening dan whitening paper. Konsumen PCC terbesar di dunia adalah USA, Jepang, Finlandia, China, dan Perancis.

Produsen GCC dan/atau PCC di Indonesia (dikutip dr berbagai sumber) di antaranya adalah PT Camco Omya, PT Bumi Kencana Murni Chemical Industry, Imerys, PT Light Calsindo Raya, dan Minerals Technologies Incorporated (MTI).

Ada 3 metode produksi CaCO3 dr batu kapur yg saat ini dikenal, yaitu metode Solvay, Caustic soda, dan recarbonizing.

Solvay method

CaCO3 + 2NaCl à Na2CO3 + CaCl2

CaCl2 + CO2 + H2O + 2NH3 à 2NH4Cl + CaCO3

CaCO3 yg di reaksi pertama msh berupa batuan kapur, sementara CaCO3 di reaksi kedua sudah berupa produk GCC atau PCC.

Caustic soda

CaCO3 + heat à CaO + CO2

CaO + H2O à Ca(OH)2

Ca(OH)2 + Na2CO3 à 2NaOH + CaCO3

Recarbonizing

CaCO3 + heat à CaO + CO2

CaO + H2O à Ca(OH)2

Ca(OH)2 + CO2 à CaCO3 + H2O

Klo semua reaksi di atas dilihat secara black box, akan diperoleh sbb:

Dr ketiga black box ini, terlihat bahwa metode recarbonizing merupakan metode yg sgt sederhana krn tidak memerlukan tambahan senyawa2 kimia lainnya (no additional chemicals). Berdasarkan analisis sederhana ini, metode recarbonizing lbh dipilih utk produksi CaCO3. Tipikal diagram alir proses utk recarbonizing adlh spt di bawah ini.

 

4 Comments (+add yours?)

  1. Dwi hartono
    Jul 28, 2012 @ 20:26:53

    Penjelasan sangat akurat dan reliable.thanks informasinya

    Reply

  2. wagekarsana
    Feb 26, 2015 @ 06:52:46

    Tq

    Reply

  3. gandha
    Jun 21, 2016 @ 10:39:47

    mantap nih..🙂

    Reply

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: