Taiheiyo Cement Corporation

Noritoshi Tamura

Shinichiro Saito

Takayuki Suzuki

Kenzaburou Kondou

Hirokazu Otani

Yoshinobu Tatsumi

In accordance with the present invention, there is provided a calcium removal method capable of reducing operation cost. A solution Lcontaining potassium or/and sodium, and calcium is passed through an ion-exchange resinto separate the solution into a solution containing potassium or/and the sodium, and a solution containing calcium. Operation cost can remarkably be decreased since potassium carbonate is not required to remove calcium as before. Timing for changing a calcium-containing water Land a salt water Ldischarged from the ion-exchange resin can be performed based on at least one measurement result selected from the group consisting of: a calcium or chlorine concentration; electrical conductivity; and pH of a fluid which is discharged from said ion-exchange resin. The solution may be a filtrate Lthat is obtained by washing a chlorine bypass dust D generated in a cement burning process, or a leachate W of a final disposal site

Calcium removal method

To minimize harmful effects on operation due to scale adhesion while accommodating increase in the amount of generated chlorine bypass dust and suppress facility cost and running cost including medical agent cost low when incineration ash and dust contained in extracted cement kiln combustion gas are subject to water treatment. [Means for Solving Problems] A water treatment systemcomprising: a dissolution tankfor dissolving a fly ash A in a water W; a dissolution tankfor dissolving a dust D contained in combustion gas extracted from a kiln exhaust gas passage running from an inlet end of a cement kiln to a bottom cyclone in a water W; and a vertical filter pressfor separately filtering a slurry Sfed from the dissolution tankand a slurry Sfed from the dissolution tankfrom each other. It is possible to install water treatment facilities-for a filtrate Lof the slurry containing fly ash discharged from the vertical filter press, and water treatment facilities-for a filtrate Lof the slurry containing ash discharged from the filtering device.

Method for washing incineration ash and dust contained in extracted cement kiln combustion gas

To provide a low price industrial salt by reducing facility and operation costs without electro-deposition and crystallization and through reduction in quantity of chemicals used. An industrial salt S obtained by the steps of: extracting a part of combustion gas from a kiln exhaust gas passage running from an inlet endof a cement kilnto a bottom cyclone; recovering dust D from the extracted gas Gand washing recovered dust; and drying a filtrate Lafter the washing in a gas stream. The industrial salt can be obtained by removing a calcium component from the filtrate and drying the filtrate from which the calcium component is removed in a gas stream. Further, from the filtrate can be removed sulfate radical, and drying the filtrate from which the calcium component is removed in a gas stream to obtain the industrial salt. For the drying can be used an exhaust gas discharged from a clinker coolerand a spray driermay be used for the drying. Drying in a stream provides industrial salt whose particle size is larger or equal to 20 &#x3bc;m and smaller or equal to 500 &#x3bc;m.

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Chiba, Japan

Noritoshi Tamura