Kemira Kemi Ab

Kemira Chemicals Oy

Neste Oy

Kemira Oy

Simo Jokinen

Pekka Knuuttila

Rolf Nilsson

Pekka Oinas

Kjell Stendahl

Vesa-Pekka Judin

Stefan J&auml;fverstr&ouml;m

Simo Salanne

Gerard Verkoijen

Bengt Hansen

Sirpa-Liisa Katariina Mattila

Anna-Mari Kristiina Stein

Maire Iida Mattila

Timo Kenakkala

Juhatuomas Vuorisalo

Process for preparing usable products from an impure ferric sulfate solution

A method for treating sludge from wastewater purification is described. In the method, a sludge is treated, which contains phosphorus and at least one metal which originates from precipitation chemicals and which is selected among divalent iron and aluminum, the pH of the sludge being adjusted to below 4, preferably below 2, for dissolving the content of the phosphorus and said metal in the sludge; the remaining sludge is separated; the solution relieved of sludge and containing phosphorus and said metal is treated for precipitation of the phosphorus content of the solution as FePO,at a pH of 2-3; and precipitated FePO,is separated. The method is characterized in that the solution which remains after separation of FePO,and which contains said metal from the precipitation chemicals, is recycled to the wastewater purification. The phosphorus content of the solution is precipitated as FePO,by adding an at least equivalent amount of Fe,.

Method for treating sludge from wastewater treatment

Method for recovering at least one metal from an acidified waste water

The invention relates to a method for the treatment of an impure aluminium oxide so that the organic impurities present therein it are converted into an insoluble and easily separable substance. According to the invention, aluminium oxide which contains organic matter as impurities is finely ground, the finely ground aluminium oxide is dissolved at an elevated temperature in sulphuric acid which has a concentration of at minimum 90% by weight, the amount of the sulphuric acid being at least stoichiometric in relation to the amount of aluminium oxide, the organic matter being carbonized into an insoluble and easily separable substance, and, if desired, the obtained mixture is treated further in order to form a solution-form or solid chemical which contains aluminium.

Method for the treatment of impure aluminium oxide

Method for treating waste water sludge

Treatment method for waste water sludge comprising phoshorous, heavy

Method for the treatment of water treatment sludge

A method for preparing anhydrous ferric chloride from a hydrous solution containing ferric chloride that contains organic substances and/or ferrous chloride. In the method, water is removed from a ferric-chloride water solution or a solution, in which at least a portion of the ferrous chloride has been converted by oxidation into ferric chloride, by drying in an atmosphere containing hydrochloric acid. The anhydrous ferric chloride is refined by sublimating it into gas phase in a chlorine-containing atmosphere and by subliming it into a pure crystalline ferric chloride.

Method for preparing ferric chloride

Growing community of inventors

Oulu, Finland

Simo Jokinen