Process Technology

Phosphoric Acid

KEMWorks offers consulting and engineering services for phosphoric acid production. We have knowledge of all the major processes including:

  • Prayon
  • Rhone Poulenc
  • Yara
  • Nissan, and
  • Jacobs

KEMWorks services include: plant audits; and revamps for increased production, recovery, and reduced enery consumption. We can provide advise on route selection specific to raw materials availability and quality, site logistics, and marketing considerations. 

  • Dihydrate - is standard for dihydrate phosphoric acid is adaptable to a wide-range of phosphate rocks. Plants have been constructed using this process, in capacities over 3,000 t/d P2O5 

Central-Prayon Process- is a two-stage Dihydrate Hemihydrate process. This high efficiency process, ± 98.5% cake efficiency, also produces a relatively strong acid, ± 36% P2O5. The process produces a "self-drying" gypsum that can be suitable for plaster boards.

Hemihydrate  - For the simplicity of a single-stage high-strength process. The process produces a stonger acid ± 40% P2O5, with a slight penalty on recovery. The process is suitable where the rock cost is low, but energy cost is high.

Hemidihydrate - is the most complex process but also produces the highest concentration filter and acid and has the highest instantaneous recovery.

Phosacid Concentration

Phosphoric acid is concentrated in an evaporator heated by low-pressure steam and operating under partial vacuum. 

KEMWorks offers designs for forced-circulation evaporators with carbon or alloys heat exchangers. The vacuum system is designed so that no vacuum pump or steam ejectors are required.

Fluorine Recovery

Fluorine may be recovered from the evaporators to produce fluorosilicic acid (FSA) at up to 25% H2SiF6.  A batch process is used, which enables FSA to be recovered at very high recovery and with as low as 100 ppm P2O5 contamination.

Fluoride Products

During the production of phosphoric acid fluoride gases are evolved that may be recovered as fluorosilicic acid (FSA or H2SiF6).

In conjunction with K-Technologies, Inc. (K-Tech) we have developed a range of technologies to convert FSA to value-added fluoride products, such as anhydrous hydrofluoric acid (AHF) and aluminum fluoride (AlF3).  In addition, K-Tech has expertise in the manufacture and marketing of specialty fluoride products, such as fluoride single and double salts, e.g. sodium fluoride and bifluoride, potassium fluoride and bifluoride, potassium fluoroborate, potassium fluotitanate and potassium fluorozirconate.

Phosphoric Acid Defluorination

Phosphoric acid defluorination using 25% of the steam of conventional technology. The process makes phosphoric acid suitable for animal feeds.


Purified Phosacid

The Research and Development Department of the J. R. Simplot Company has successfully developed a membrane based system for the purification of wet process phosphoric acid after four years of intensive research. A first-of-a-kind, 30,000 t/y solution purification plant using this technology successfully started up in 1996 to produce high quality, fertigation (drip) grade phosphoric acid.

Process Advantages:

  • A high value added product is manufactured from wet process phosphoric acid.
  • No solvents are used in the process.
  • Commercially proven.
  • Only by-product is a raffinate acid stream.
  • Low capital and operating costs.
  • Produces a technical grade acid.
  • Available through a licensing agreement with KEMWorks Technology.
  • Process is flexible - high levels of product quality can be met through multiple stages of membrane filtration.
  • Simple, easy to operate process.

Uranium Extraction

Several companies extracted uranium as yellow cake from phosphoric acid until the price dropped below the cost of production in the early 1990s.

Now uranium prices have rebounded and nuclear energy is considered by many one of the best alternatives to meet climate change targets and reduce dependence on foreign oil.

In conjunction with K-Technologies, KEMWorks offers the conventional solvent extraction (SX) process using DEPA-TOPO that became the standard in the 1980s. We have also developed two Advanced Technologies that offer significant reductions in capital and operating costs, and eliminates the disadvantages of the kerosene carrier used in the SX process.

K-Technologies operates a pilot plant near Lakeland where we can test your phosphoric acid and provide an estimate of capital and operating costs for any of these three technologies.

Rare Earth Elements

The supply of rare earths is considered to be at high risk because global production is concentrated in a few countries some of which have relatively low political stability ratings.

Depending on the rock source and processing technique, wet process phosphoric acid contains varying quantities of the Rare Earth Elements (REE), and other valuable strategic metals, including  vanadium and uranium. There is a significant potential for the recovery of rare earths, and other valuable materials from wet process phosphoric acid.

Yttrium and rare earths can be extracted using a combination of several techniques developed by K-Technologies including precipitation, continuous ion-exchange, and continuous chromatographic separation. The technique is particularly attractive when combined with uranium extraction. Potential revenue from a benchmark Moroccan acid is provided. For K09 Moroccan phosphate the value of the REE content is over $50 / t of P2O5 treated and the recovery cost is about $10 (prices at November 2011).

 Fertilizers

KEMWorks offers process technology for a range of fertilizer products including:

  • MAP, DAP, SSP and GTSP granulation.
  • Powder (Run-of-Pile or ROP) SSP and TSP.
  • Granular NPKs - including "customised fertilizers" fortified with micronutrients.

These technologies are well proven with dozens of reference plants in South America. All feature:

Granular MAP/DAP/TSP

Features of the technology:

  • JPipe reactor techniques commercialized since 1986. The JPipe reactor functions alone for MAP and in conjunction with a preneutralizer for DAP at high capacities.
  • Single train plant up to 200 tonnes/hour DAP or MAP.
  • Optimization of water balance provides flexibility of acid strength and source.
  • An Advanced Recycle Control System (ARCS) reduces the recycle ratio by about 30% compared with conventional processes resulting in lower capital cost.
  • Fuel and electricity consumption reduced by about 25% compared with conventional processes.
  • Simplicity in operation leads to lower maintenance costs.

With increasing fuel and raw material prices, the economics of producing granulation products has been adversely affected. We can also offer a number of proven methods to modify granulation plants to reduce energy costs, including warm-air recycle, waste heat ammonia vaporizers, and bulk flow cooling.

Powder (ROP) SSP/TSP

Features of the technology:

  • Designs are available from 10 to 130 t/h using Belt-Den technology.
  • Operations since 1984 with direct dilution of the 98% H2SO4 with either water or H2SiF6.
  • No liquid effluents when diluting with H2SiF6. • The turbine mixer-belt den combination produces a low density, porous product that is easy to granulate.
  • For SSP permits operation with rock slimes or ground phosphate rock in the form of slurry with H2SiF6 from the scrubbing system.

Granular NPKS with micronutrients

Features of the technology:

  • Standard designs available from 10 to 100 t/h.
  • Flexibility in raw material source: ROP SSP and TSP, DAP, MAP, Urea, Ammonium Sulfate, and Potash.
  • An improvement method to accurate fortify the fertilizer with micronutrients, including: Zinc, Boron, Copper, and Manganese. • Addition of elemental sulphur for high S grades.
  • An Advanced Recycle Control System (ARCS) minimizes recycle ratio for lower capital cost.
  • No Propriety Equipment for a more competitively priced plant.

Animal Feed Ingredients

KEMWorks offers technology for the production of mini-granular animal feed ingredients. Animal feeds require a P/F ratio of at least 100:1 so phosphoric acid used to produce mono- and dicalcium phosphate (MCP/DCP) must usually be defluorinated. KEMWorks offers a simple system for phosphoric acid defluorination using air-stripping.  Defluorinated phosphate rock (DFP) is made from phosphate rock, phosphoric acid, and soda ash. In this product the fluorine is removed by calcination.

The Improved Hard Process (IHP)

The Improved Hard Process is a Kiln-based phosphoric acid process that may have major environmental and sustainability advantages over wet-process phosphoric acid routes for low-grade phosphate ores. It produces a higher quality phosphoric acid that through fertigation practices allows more efficient utilization in crops and allows for less surface and ground water contamination at the point of use.

The Improved Hard Process (IHP) may offer capital and operating cost advantages with the Wet Acid Process for low-grade ores.

KEMWorks has provided third-party reviews of the process and can provide you with an assessment of its suitability for your phosphate and yur particular site conditions.

Sulfuric Acid

Our associates provide consulting services for sulfuric acid, ammonia scrubbing, sulfur handling and cogeneration.

Environmental

  • Waste Minimization
  • Environmental Controls - fume scrubbers
  • Plant Closure and Remediation