Sulfur-Melt Potash Granule Compaction

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Solution Overview

Problem

Existing processes for producing sulfur-containing potash granules are complex, energy-intensive, and result in granules with unsatisfactory mechanical stability and low yield, particularly after moist weathering.

Innovation Solution

A process involving mixing a potassium chloride-containing finely divided raw material with a sulfur melt and subjecting the mixture to compaction, eliminating the need for micronization or emulsification and reducing the pressing force required for granule formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional granulation processes (compaction or buildup agglomeration) are used to produce potash granules, then granule size is increased, but mechanical stability and adhesion between particles deteriorate

Engineering Contradiction:
Improvegranule sizeVSAvoidmechanical stability
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The invention changes the physical-chemical parameters of the granulation process by using a molten sulfur binder at elevated temperatures (above sulfur's melting point of 115°C). This temperature parameter change enables the sulfur to be in liquid state during granulation, providing superior binding properties that enhance mechanical stability while forming granules of desired size. The molten sulfur penetrates between particles and solidifies upon cooling, creating strong interparticle bonds.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite granule structure where potassium chloride particles are bound together by sulfur. This composite material approach combines the properties of both components: the potassium chloride provides the fertilizer function while the sulfur acts as a binding matrix that enhances mechanical strength. The sulfur-KCl composite structure resolves the contradiction by providing both adequate granule size and improved mechanical stability through the synergistic combination of materials.

Inventive Principle:
Principle #40Composite materials

2Strength

If binders are added to improve adhesion forces between particles, then mechanical strength is improved, but process complexity and cost increase

Engineering Contradiction:
Improveadhesion forcesVSAvoidprocess complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention employs sulfur, which is inherently present in fertilizers as a nutrient component, to serve dual functions: as a plant nutrient and as a binder. This self-service approach eliminates the need for separate binder additives, simplifying the process while improving adhesion. The sulfur that would otherwise be merely a nutritional component now also provides the binding function, reducing process complexity and eliminating the need for additional binder handling equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The sulfur component performs multiple functions simultaneously: it serves as a plant nutrient (sulfur is an essential secondary nutrient), as a binder providing mechanical strength, and as a process simplifier by eliminating the need for separate binder additives. This multi-functionality resolves the contradiction by making the binder an integral part of the fertilizer composition rather than an additional component, thereby reducing process complexity while enhancing adhesion forces.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If micronized sulfur is used to produce sulfur-containing granules, then sulfur distribution is improved, but yield decreases and additional processing steps are required

Engineering Contradiction:
Improvesulfur distributionVSAvoidyield
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention changes the physical state parameter of sulfur from solid (micronized) to liquid (molten) during the granulation process. By heating sulfur above its melting point, it becomes a流动 liquid that can uniformly distribute among particles during the granulation process itself, eliminating the need for pre-micronization. The molten sulfur flows and penetrates between particles, achieving uniform distribution without requiring additional micronization equipment or processing steps, thereby maintaining high yield.

Inventive Principle:
Principle #35Parameter changes

4Quantity of substance

If high pressing forces are applied during compaction to form granules, then granule density is increased, but particle deformation and dust formation increase

Engineering Contradiction:
Improvegranule densityVSAvoiddust formation
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The invention utilizes the phase transition of sulfur from solid to liquid (melting) during compaction. The molten sulfur acts as a lubricant and binding agent simultaneously, allowing particles to consolidate into dense granules without requiring excessively high pressing forces. The liquid sulfur fills voids between particles and creates strong bonds upon solidification, achieving high density while reducing mechanical stress that would otherwise cause particle deformation and dust generation.

Inventive Principle:
Principle #36Phase transitions

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The process produces sulfur-containing potash granules with high fracture strength, low abrasion, and improved mechanical stability even after moist weathering, with higher yields compared to using micronized sulfur, and without the need for conventional binders.

Implementation Method 1

binders which improve the adhesion forces between the particles of the finely divided starting material and thus cohesion of the particles in the granules

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

deformation of the primary particles in the contact region, for example by plastic deformation, which considerably increases the adhesion of the primary particles to one another

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 3

Solid-state bridges can also be formed between the primary particles as a result of frictional heat

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentUS20220402766A1Method for producing sulphur-containing potash granules
Publication Date: 2022.12.22 K S AKTIENGESSSCHAFT

AI summary

The invention relates to a method for producing sulphur-containing potash granules from fine-particle, potassium-chloride-containing raw materials and elementary sulphur, and to the sulphur-containing potash granules obtained with this method. The method comprises the following steps a) and b): a) mixing a potassium-chloride-containing, fine-particle raw material with a sulphur melt in a quantity of 2 to 30 wt. %, in particular 3 to 25 wt. %, preferably 5 to 23 wt. % and particularly preferably 8 to 20 wt. % in relation to the total amount of sulphur melt and fine-particle raw material, producing a mixture of fine-particle raw material and molten sulphur; and b) compacting the mixture of fine-particle raw material and molten sulphur obtained in step a). The invention also relates to the use of sulphur melts in the production of potassium chloride granules by compacting a potassium-chloride-containing, fine-particle raw material to reduce the pressing force during compacting, and to the use of sulohur melts to improve the mechanical strength of potash granules, containing potassium chloride, in particular potash granules obtained by compacting a sulphur- and potassium-chloride-containing, fine-particle raw material.