Fertilizers & Chemicals Ltd.

Chemicals & Phosphates, Ltd.

Dahlia Simeona Greidinger

Shimon Epstein

Arie Gulko

Liuba Cohen

Benedict Cytter

Liuba Cohen Nee Girshowitsh

The present invention relates to a method for the manufacture of an improved ureaform fertilizer. The method consists in the condensation of urea and formaldehyde carried out in a controlled system having a pH between 3.5 and 4.2 wherein the overall concentration of the reagents is in the range of 20 to 40% by weight. The ratio between the reagents is between 1.2 to 1.5 moles of urea to 1 mole of formaldehyde and the temperature of the reaction is kept between 15.degree. C. to 40.degree. C. Examples of preferred controlled systems are H.sub.3 PO.sub.4 -KH.sub.2 PO.sub.4 and H.sub.3 PO.sub.4 -NH.sub.4 H.sub.2 PO.sub.4. The method can also be performed in a continuous manner giving rise to an overall quantitative yield, and being temperature self-regulating. The ureaform obtained by the method has an activity index of over 75 and excellent physical properties.

Method for the manufacture of improved ureaform fertilizer

The present invention relates to a method for improving the smooth functioning of drip irrigation utilizing some nitrogen-based compositions. The method consists in providing to the solution supplied to drip irrigation, a pH from about 0.05 to about 3.0, utilizing an aqueous solution of urea nitrate having a weight concentration from about 28 to 0.1 percent respectively. The aqueous solutions utilized in drip irrigation may also contain various fertilizer substances thus providing the desired N:P:K formulations.

Method and composition for improving the functioning of drip irrigation

The present invention relates to a new fertilizer compound of the ureaform type and to a method for the production thereof. The new ureaform compound is characterized by the low average degree of polymerization between urea and formaldehyde. The new compound has a nitrogen content of over 41% by weight and consists of cold water soluble nitrogen as the main fraction and cold water insoluble as the second fraction which is substantially free of hot water insoluble nitrogen. The new ureaform compound is obtained by the condensation of urea and formaldehyde at a correct ratio between the reagents and termination of the reaction at a stage wherein excessive polymerization is prevented. The reaction is carried out in a controlled system with a pH in the range of 3.5 to 4.2. Particularly useful are the systems H.sub.3 PO.sub.4 -KH.sub.2 PO.sub.4 and H.sub.3 PO.sub.4 -NH.sub.4 H.sub.2 PO.sub.4. The new compound successfully combines the advantage of both mineral water soluble nitrogen fertilizers and organic water insoluble slow-release nitrogen sources.

Fertilizer compound of the ureaform type and a method for the production

The present invention relates to a process for the direct manufacture of crystalline urea phosphate. The process consists in the reaction of solid urea with ortho-phosphoric acid in a substantially anhydrous form. A concentrated phosphoric acid with above 90% by weight H.sub.3 PO.sub.4 can be used as starting reagent. A preheating of the phosphoric acid at 60.degree.-90.degree.C is preferred in order to induce the spontaneous reaction with the solid urea. The urea phosphate product obtained is ready for use without any further operation. Desired micronutrients such as Mg, Co, Fe, Zn, Cu, Mn may be incorporated in the initial ortho-phosphoric acid prior to the reaction with the solid urea.

Growing community of inventors

Haifa, Israel

Dahlia Simeona Greidinger