The disclosure relates to a plant for thermal treatment of solid material to decrease the content of heavy metal elements. The plant comprises one reactor for heating the solid material, which is arranged to have both an oxidizing atmosphere and a reducing atmosphere, and the plant includes a hot gas generator, which is arranged to provide hot gas to the reactor. The disclosure also relates to a method for thermal treatment of solid material and to a method for producing fertilizer precursor.

The disclosure relates to a plant for thermal treatment of solid material to decrease the content of heavy metal elements. The plant comprises one reactor for heating the solid material, which is arranged to have both an oxidizing atmosphere and a reducing atmosphere, and the plant includes a hot gas generator, which is arranged to provide hot gas to the reactor. The disclosure also relates to a method for thermal treatment of solid material and to a method for producing fertilizer precursor.

The present invention relates to fertilizer compositions comprising phosphate rock powder (PRP) and surface-reacted calcium carbonate (SRCC) and optionally a binder.

The present invention relates to fertilizer compositions comprising phosphate rock powder (PRP) and surface-reacted calcium carbonate (SRCC) and optionally a binder.

A method is provided herein for developing fertilizer that may include the steps of combining a source of micronutrients with at least a first nitrogen source, a first phosphorus source, a first potassium source, or a first additional source. The first source of micronutrients may be derived from the combustion of a biomass feedstock via a biomass combustion system. The first source of micronutrients may comprise, for example, a biomass ash or a wood ash. The fertilizer may be organic or inorganic and may be used for a variety of purposes. The fertilizer may be in powder, granular, or pelletized form.

A method is provided herein for developing fertilizer that may include the steps of combining a source of micronutrients with at least a first nitrogen source, a first phosphorus source, a first potassium source, or a first additional source. The first source of micronutrients may be derived from the combustion of a biomass feedstock via a biomass combustion system. The first source of micronutrients may comprise, for example, a biomass ash or a wood ash. The fertilizer may be organic or inorganic and may be used for a variety of purposes. The fertilizer may be in powder, granular, or pelletized form.

A method of calcination includes providing a raw material including whitlockite Ca.sub.9(Mg,Fe.sup.2+)[PO.sub.3(OH)|(PO.sub.4).sub.6], and/or iron phosphate FePO.sub.4, and/or aluminum phosphate AlPO.sub.4 and/or fluorapatite Ca.sub.5(PO.sub.4).sub.3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.

A method of calcination includes providing a raw material including whitlockite Ca.sub.9(Mg,Fe.sup.2+)[PO.sub.3(OH)|(PO.sub.4).sub.6], and/or iron phosphate FePO.sub.4, and/or aluminum phosphate AlPO.sub.4 and/or fluorapatite Ca.sub.5(PO.sub.4).sub.3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.

A method of calcination includes providing a raw material including whitlockite Ca.sub.9(Mg,Fe.sup.2+)[PO.sub.3(OH)|(PO.sub.4).sub.6], and/or iron phosphate FePO.sub.4, and/or aluminium phosphate AlPO.sub.4 and/or fluorapatite Ca.sub.5(PO.sub.4).sub.3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.

A method of calcination includes providing a raw material including whitlockite Ca.sub.9(Mg,Fe.sup.2+)[PO.sub.3(OH)|(PO.sub.4).sub.6], and/or iron phosphate FePO.sub.4, and/or aluminium phosphate AlPO.sub.4 and/or fluorapatite Ca.sub.5(PO.sub.4).sub.3F; providing an alkaline-sulfuric compound as an additive; and calcining a mixture of the raw material with the additive to obtain a product, including a citrate soluble phosphate compound.