Cement company begins burning rubble from disasters

July 12, 2011

With rubble proving a major barrier to reconstruction in communities devastated by the Great East Japan Earthquake, Taiheiyo Cement Corp. began incinerating the debris from the Iwate Prefecture cities of Ofunato and Rikuzentakata from June 22.

Cement companies normally include waste in manufacturing cement so they are equipped to handle rubble.

Experts estimate that about 20 million tons of rubble were created by the disaster.

Of that amount, there is 5.83 million tons in Iwate Prefecture alone.

The cities of Ofunato and Rikuzentakata will have to dispose of 1.71 million tons over a three-year period.

Taiheiyo Cement's Ofunato plant was also hit by the disasters, and cement production will not resume there until November.

The burning of rubble began at a furnace that was not damaged by the tsunami.

About 300 tons of rubble that city workers have selected and crushed into a size less than five centimeters will be incinerated.

Company President Keiji Tokuue said, "The support that we can provide will involve making up our minds to process the rubble."

The company began burning the rubble even before the central government's supplementary budget that will provide funds for the processing of the debris passed the Diet.

Iwate prefectural government officials want to ask Taiheiyo Cement to also handle the rubble from other cities in the prefecture.

One official said, "Once the plant resumes regular operations in November it will be able to incinerate a considerable volume."

Cement companies have often recycled waste products. In fiscal 2010, the cement industry as a whole took in about 25 million tons of waste, in the form of coal ash, sludge and scrap lumber, to use as cement materials for fuel.

The cement industry takes in so much waste that, according to experts, if the industry did not do so Japan's waste disposal grounds would become full in half the number of years.

One problem, however, is the salt that has seeped into the rubble as a result of the tsunami that followed the March 11 quake.

Along with the salt from seawater, there are also other elements that would have to be burned at high temperatures to prevent the release of toxic elements such as dioxin.

An official at Taiheiyo Cement's Ofunato plant said the salt and the need to burn at high temperatures would place an additional burden on the furnace.

For that reason, the period until the end of August will be considered an experimental one. If no problems are found, the amount of rubble incinerated will be gradually increased.

To allow the company to use the rubble as cement materials, the Ofunato city government is preparing a facility to reduce the concentration of salt.

The Taiheiyo Cement official said, "Rebuilding of the community cannot begin unless the rubble is processed. We want to be able to use the rubble in cement production."

Mitsubishi Materials Corp. also has cement plants in Higashidori, Aomori Prefecture, and Ichinoseki, Iwate Prefecture.

However, the company has no specific plans now to accept rubble from the Tohoku region because of issues related to sorting out the rubble and removing the salt.

(This article was written by Shuichi Doi and Ryo Shimura.)

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The cylindrical furnace at Taiheiyo Cement's Ofunato plant used to incinerate rubble. (Photo by Shuichi Doi)

The cylindrical furnace at Taiheiyo Cement's Ofunato plant used to incinerate rubble. (Photo by Shuichi Doi)

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  • The cylindrical furnace at Taiheiyo Cement's Ofunato plant used to incinerate rubble. (Photo by Shuichi Doi)

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