Flowable mixture including elemental sulfur and hydrated clay and method for producing the same

Abstract

The present invention is directed to a flowable mixture including: a) a hydrated clay suspension and b) sulfur derived from elemental sulfur. Preferably, the flowable mixture includes elemental sulfur particles and a hydrated, absorbent clay, such as bentonite clay. The flowable mixture is preferably a liquid mixture for use as a fertilizer or fungicide.

Claims

1. A stable flowable mixture including: a) a hydrated clay suspension including between 0.5-7.5 wt. % absorbent clay based on the total weight of the flowable mixture; b) 40-60 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture; and c) optional additives; wherein all the sulfur in said stable flowable mixture is elemental sulfur provided as a suspension of elemental sulfur particles having a particle size of less than 50 μm, and said stable flowable mixture does not include any surfactants, and wherein said flowable mixture includes at least 12.5 wt. % water.

2. The stable flowable mixture of claim 1, wherein said flowable mixture does not include any bio-based suspending agent.

3. The stable flowable mixture of claim 1, wherein said hydrated clay suspension consists of only at least one absorbent clay with at least one solvent.

4. The stable flowable mixture of claim 3, wherein said hydrated clay suspension consists of only bentonite as said absorbent clay and water as said solvent.

5. The stable flowable mixture of claim 4, wherein said bentonite is selected from the group consisting of calcium bentonite, sodium bentonite, and combinations thereof.

6. The stable flowable mixture of claim 1, wherein said stable flowable mixture has a viscosity higher than 1 cP (20° C.).

7. The stable flowable mixture of claim 1, wherein said suspension of elemental sulfur particles is concentrated to include 70-80% elemental sulfur, based on the total weight of the suspension of elemental sulfur particles, in an aqueous media.

8. The stable flowable mixture of claim 1, wherein all of said sulfur has a particle size of less than 1.5 um.

9. The stable flowable mixture of claim 1, wherein said additives are selected from the group including 0-5 wt. % anti-freeze, 0-5 wt. % anti-foam, 0-10 wt. % diatomaceous earth, 0-20 wt. % plant nutrients and combinations thereof, based on the total weight of the flowable mixture.

10. The stable flowable mixture of claim 1, further including propylene glycol as an anti-freeze and polydimethylsiloxane as an anti-foam.

11. The stable flowable mixture of claim 1, wherein said elemental sulfur is provided as molten elemental sulfur.

12. The stable flowable mixture of claim 1, including 50-55 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture.

13. The stable flowable mixture of claim 1, including 51-53 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture.

14. The stable flowable mixture of claim 1, wherein the only solvent in the flowable mixture is water.

15. A fertilizer or fungicide composition including: the stable flowable mixture of claim 1, wherein said flowable mixture has fertilizing and/or fungicidal activity.

16. The fertilizer or fungicide composition of claim 15, wherein said additives are plant nutrients selected from the group consisting of boron, nitrogen, phosphorus, potassium, iron, copper, zinc, manganese, magnesium and combinations thereof.

17. The stable flowable mixture of claim 1, further comprising 12.5-37.25 wt. % water.

18. The stable flowable mixture of claim 1, wherein said flowable mixture has a viscosity >1 cP.

19. A stable flowable mixture consisting of: a) a hydrated clay suspension including 0.5-7.5 wt. % absorbent clay based on the total weight of the flowable mixture, wherein the absorbent is bentonite; b) 40-60 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture; c) additives selected from the group consisting of anti-freeze, anti-foam, diatomaceous earth, plant nutrients and combinations thereof, and d) at least 12.5 wt. % water, wherein said elemental sulfur is provided as a suspension of elemental sulfur particles having a particle size of less than 50 μm; wherein said flowable mixture does not include any preservatives or surfactants; wherein the only solvent in the flowable mixture is water and wherein said flowable mixture does not include any bio-based suspending agent.

20. The stable flowable mixture of claim 1, wherein said stable flowable mixture is stable after 14 days at an elevated temperature of 54° C.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) A flowable mixture containing a hydrated clay suspension, sulfur derived from elemental sulfur and optional additives is provided. In one embodiment, the flowable mixture includes a hydrated clay suspension and elemental sulfur particles suspended in the hydrated clay suspension. The flowable mixture preferably includes 40-60 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture, for use as a fertilizer or fungicide.

(2) The flowable mixture is more stable than previous compositions as it preferably does not use any bio-based suspending agents, which are prone to biological attack and thereby cause the suspended concentrate to fail. Such bio-based suspending agents that are preferably excluded from the present flowable mixture include, but are not limited to xanthan, guar and cellulose gums.

(3) In a preferred embodiment, the flowable mixture does not include any surfactants or preservatives. Such surfactants or preservatives that are preferably excluded from the present flowable mixture include, but are not limited to biocides, biostats, and emulsion stabilizing water and oil based surfactants.

(4) In a preferred embodiment, the flowable mixture only uses “organically” allowed ingredients thereby allowing the flowable mixture to be listed as an organic pesticide, fertilizer or fungicide. “Organically” allowed ingredients are those that are allowed by the United States National Organic Program, such as, for example non-synthetic natural substances (205.600) and synthetic substances allowed in organic crop production (205.601).

(5) In one embodiment of the present invention, the hydrated clay suspension is prepared by combining an absorbent clay, preferably bentonite, with a solvent, preferably water. In one such embodiment, water is the only solvent present in the hydrated clay suspension. In another preferred embodiment, the hydrated clay suspension consists of only absorbent clay and water. Preferably, the hydrated clay suspension includes between 0.5-7.5 wt. %, more preferably 0.5-5.0 wt. %, and even more preferably between 0.5-3 wt. % absorbent clay, such as bentonite, based on the total weight of the flowable mixture. The bentonite is preferably calcium and/or sodium bentonite. Preferably, the absorbent clay is hydrated in water until the viscosity of the hydrated clay suspension is higher than water itself, i.e. >1 cP and more preferably >10 cP (20° C.).

(6) In one embodiment, the elemental sulfur is provided as a suspension of elemental sulfur particles and combined with the hydrated clay suspension. Preferably, the suspension of elemental sulfur particles is prepared by thoroughly homogenizing molten elemental sulfur with a solvent. In a preferred embodiment, the only solvent in the suspension of elemental sulfur particles in water. Preferably, the suspension of elemental sulfur is concentrated to include 70-80 wt. % elemental sulfur in an aqueous media based on the weight of the suspension. The flowable mixture preferably includes elemental sulfur particles of a low particle size, thereby allowing for greater performance in the field as a fertilizer or fungicide. In preferred embodiments, the elemental sulfur particles in the suspension has a particle size of less than 50 um, more preferably less than 20 um, more preferably less than 5 um, and even more preferably less than 1.5 microns.

(7) Furthermore, the flowable mixture may include additives such as 0-5 wt. % anti-freeze, such as propylene glycol, and 0-5 wt. % anti-foam, such as polydimethylsiloxane, based on the total weight of the flowable mixture. Optionally, to further incorporate an insecticidal property, diatomaceous earth may be included as an additive between 0-10 wt. %, and more preferably 0-5 wt. % based on the total weight of the flowable mixture. In a preferred embodiment, the flowable mixture does not include any preservatives and/or surfactants.

(8) In a preferred embodiment, the flowable mixture consists of: a) a hydrated clay suspension, b) 40-60 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture; c) 0-5 wt. wt. % anti-freeze, such as propylene glycol, based on the total weight of the flowable mixture; d) 0-5 wt. % anti-foam, such as polydimethylsiloxane, based on the total weight of the flowable mixture; e) 0-10 wt. %, or more preferably 0-5 wt. %, diatomaceous earth based on the total weight of the flowable mixture, such that the only solvent in the flowable mixture is water.

(9) In one embodiment, the hydrated clay suspension, suspension of elemental sulfur particles, and optional additives are thoroughly mixed until a>1 cP (20° C.), and more preferably >10 cP (20° C.), viscosity is met. In one embodiment, the mixture of the hydrated clay suspension, the suspension of elemental sulfur particles, and the optional additives are mixed for 1-3 hours until a>1 cP (20° C.), and more preferably >10 cP (20° C.), viscosity is met. In an alternate embodiment, molten elemental sulfur is directly homogenized with a mixture of the hydrated clay suspension and optional additives. In one embodiment, the hydrated clay suspension and sulfur derived from elemental sulfur, preferably in the form of elemental sulfur particles, is provided in such quantities as to arrive at a flowable mixture including 40-60 wt. %, more preferably 50-55 wt. %, and even more preferably 51-53 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture. Preferably no heat is added during the formation of the flowable mixture and the mixture is formed around room temperature, i.e. 20 and 26° C. (68 and 79° F.).

(10) In a preferred embodiment, the flowable mixture includes 40-60 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture, for use as a fertilizer or fungicide. The term “fertilizer” is used to designate any substance (natural or of synthetic origin) that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants. The term “fungicide” is used to designate any substance (natural or of synthetic origin) that is applied to soils or to plant tissues used to inhibit fungi or fungal spores.

(11) Optionally, the flowable mixture can by combined with other plant nutrients including boron, nitrogen, phosphorus, potassium, iron, copper, zinc, manganese, magnesium or combinations of the foregoing. These components can be present in the flowable mixture in amounts of from about 0 wt. % to about 20 wt. % and more preferably, 0 wt. % to about 10 wt. %, based on the total weight of the flowable mixture. In an alternate embodiment, these plant nutrients may be combined with the hydrated clay suspension and/or suspension of elemental sulfur particles prior to the formation of the flowable mixture.

(12) In a preferred embodiment, the flowable mixture consists of: a) a hydrated clay suspension, b) 40-60 wt. % sulfur derived from elemental sulfur, based on the total weight of the flowable mixture; c) 0-5 wt. wt. % anti-freeze, such as propylene glycol, based on the total weight of the flowable mixture; d) 0-5 wt. % anti-foam, such as polydimethylsiloxane, based on the total weight of the flowable mixture; e) 0-10 wt. %, or more preferably 0-5 wt. %, diatomaceous earth based on the total weight of the flowable mixture, f) 0 wt. % to about 20 wt. %, or more preferably 0 wt. % to about 10 wt. %, at least one plant nutrient based on the total weight of the flowable mixture, such that the only solvent in the flowable mixture is water.

EXAMPLES

(13) General Procedure:

(14) The bentonite clay utilized under this invention was purchased from Vanderbilt Minerals, LLC, Mineral Technologies, and other sources of refined bentonite clay and are not limited to these sources. The bentonite clay was then hydrated by mixing with water and stirred, with or without heat, until the viscosity of the clay was higher than water itself. An aqueous suspension of elemental sulfur particles with additional additives, as provided below in Table 1, were then added and stirred until a homogeneous suspension is formed providing a flowable mixture having a viscosity >1 cP and more preferably >10 cP (20° C.).

(15) TABLE-US-00001 TABLE 1 Examples of stable flowable mixtures (amounts in wt. %) A B C D E F G H I Bentonite Clay 2 2 2 2 5 1 2 2 2 Water 23.5 18 18.25 23 37.25 12.5 20.75 20.75 15.75 Sulfur Suspension 74.25 74.75 74.25 74.25 57 85.75 71.5 71.5 71.5 including 70% Elemental Sulfur Propylene Glycol 0 5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 polydimethylsiloxane 0.25 0.25 5 0.25 0.25 0.25 0.25 0.25 0.25 Diatomaceous 0 0 0 0 0 0 5 0 0 Earth Disodium 0 0 0 0 0 0 0 5 0 Octaborate Tetrahydrate Tribasic Copper 0 0 0 0 0 0 0 0 10 Sulfate

(16) The flowable mixtures were then placed for stability testing. The EPA Guidelines on Stability that issued on Nov. 16, 2012 to the Office of Pesticide Programs (OPP) relating to “Accelerated Storage Stability and Corrosion Characteristics Study Protocol” were followed. As provided in the EPA Guidelines, accelerated storage stability can be used to fulfill EPA data requirements. OPP has determined that this study, conducted for 14 days at an elevated temperature (54° C.), provides adequate data in certain circumstances to allow EPA to make a regulatory finding regarding the stability of the product and the effect of the formulation on the product packaging. All of the examples containing the bentonite clay demonstrated a stable mixture under these conditions (Table 1), as well as those set up under high vibration conditions; whereas, those not containing the clay resulted in a hardened bottom layer of conglomerated sulfur. Particle size evaluation of these flowable mixtures showed all examples to be less than 1.5 microns.

(17) Although the present invention has been disclosed in terms of a preferred embodiment, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.