Soil conditioner, and soil conditioner manufacturing process

Patent metadata

Field	Value
Publication number	US-9902657-B2
Application number	US-201514867987-A
Country	US
Kind code	B2
Filing date	Sep 28, 2015
Priority date	Oct 17, 2014
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Industrial demand for hexafluorosilicic acid (H 2 SiF 6 ) is often lower than the amount produced from fluoride recycling processes. One alternative for using this surplus is manufacturing a soil conditioner by neutralizing the hexafluorosilicic acid with calcium oxide (CaO) inside an open, Kullman type reactor. The reaction ensures alkalinity to the soil conditioner having a pH of about 10, moisture less than about 40%, phosphorus (P 2 O 5 ) at about 2.5%, calcium at about 22%, about 0.5% magnesium, about 10% silicon (about 30% to 40% water-soluble), about 18% fluoride, neutralization power of about 5% to 15%, and total neutralization power of about 5% to 12%. The resulting product, called AgroSiCa, is easily manageable with very high contents of Ca and Si (total and soluble), and also contains Mg, P, Fe, Zn, and F. When applied to soil, it contributes to the supply of nutrients, provides a better root growth and improves the plants development.

First claim

The invention claimed is:

1. A soil conditioner manufacturing process, comprising neutralizing hexafluorosilicic acid (H 2 SiF 6 ) with an excess of calcium oxide (CaO) inside a reactor to produce an alkaline soil conditioner.

2. The soil conditioner manufacturing process of claim 1 , wherein the reactor is a mixing reactor.

3. The soil conditioner manufacturing process of claim 1 , wherein a retention conveyor belt and a ventilation system, are positioned in series with the reactor.

4. The soil conditioner manufacturing process of claim 3 , wherein at least one of the hexafluorosilicic acid (H 2 SiF 6 ) and calcium oxide (CaO) comprises an amount of moisture, and wherein an exothermal reaction between the hexafluorosilicic acid (H 2 SiF 6 ) and the calcium oxide (CaO) releases sufficient heat for boiling the moisture, and wherein no more than 5 seconds after feeding the reactor, material contained inside the reactor is poured boiling onto the conveyor belt.

5. The soil conditioner manufacturing process of claim 4 , wherein the hexafluorosilicic acid (H 2 SiF 6 ) is simultaneously fed with the calcium oxide (CaO) into the reactor to produce an alkaline soil conditioner with pH of about 9 to about 12.

6. The soil conditioner manufacturing process of claim 5 , wherein the moisture content in the material poured onto the conveyor belt is removed as vapor through forced ventilation provided by a gas exhaust system.

7. The soil conditioner manufacturing process of claim 1 , wherein the soil conditioner comprises about 20% to about 25% calcium by weight.

8. The soil conditioner manufacturing process of claim 1 , wherein the soil conditioner comprises about 8% to about 12% silicon by weight.

9. The soil conditioner manufacturing process of claim 8 , wherein 30% to 40% of the silicon is water-soluble.

10. The soil conditioner manufacturing process of claim 1 , wherein the soil conditioner further comprises macronutrients and/or micronutrients essential for plant development.

11. A soil conditioner comprising moisture of less than about 40% by weight and, comprising by weight relative to total mass of the soil conditioner, a total P 2 O 5 concentration of about 0.2% to about 3.0%, soluble P 2 O 5 in citric acid of about 0.2% to about 3.0%, and concentration of P 2 O 5 soluble in neutral ammonium citrate+water of about 0.1% to about 2.0% with less than about 1% water-soluble; calcium concentration of about 20% to about 25% and magnesium concentration of about 0.4% to about 0.6%; total silicon concentration of about 8% to about 12%, about 30% to about 40% being water-soluble; concentration of soluble fluoride in hydrochloric acid of about 15% to about 20%; citric acid of about 0.2% to about 0.5% and neutral ammonium citrate of about 0.2% to about 0.5%, and water at about 0.02% to about 0.05%; and wherein a neutralization power is about 5% to about 15%, and a relative total neutralization power is about 5% to about 12%.

12. The soil conditioner, in accordance with claim 11 , comprising a powder, bran, granule, or pellet.

13. The soil conditioner, in accordance with claim 11 , comprising macronutrients and/or micronutrients essential to plant development, and an even distribution of nutrients.

Assignees

• Vale Sa
• Vale Fertilizantes S A

Inventors

• Rodrigues Sergio Leite
• Guimarães Guilherme Luiz Roberto
• Ramos Silvio Júnio
• Ribeiro Do Valle Lucas Alberth
• Pereira Hamilton Seron
• Tarso De Souza Costa Enio
• Siqueira Jose Oswaldo

Classifications

• C05G3/80

  Soil conditioners · CPC title

• C05D9/00

  Other inorganic fertilisers · CPC title

• C05B17/00 Primary

  Other phosphatic fertilisers, e.g. soft rock phosphates, bone meal · CPC title

• C05D3/02

  from limestone, calcium carbonate, calcium hydrate, slaked lime, calcium oxide, waste calcium products · CPC title

• C05D3/00

  Calcareous fertilisers (C05D7/00 takes precedence) · CPC title