Inorganic Chemicals and Minerals Analysis

Anderson Materials Evaluation is often faced with the analysis and characterization of inorganic chemicals and minerals.  These may be input ingredients to make other materials, but they are also often directly used in their mineral form or a purified form.  It may be important to measure their degree of hydration overall or just at a surface.  It may be important to measure the bulk or the surface impurities.  Sometimes we examine them to see what the affects of aging or environment are on them.  Minerals or the surface chemistry of an otherwise pure inorganic compound may be very complex.  AME can very often develop even complex, quantitative, multi-phase chemistry in an inorganic material.

These inorganic chemicals or minerals may be used as fill materials for plastics, paints, sealants, adhesives, or other composite materials.  They may be the raw materials for glass making or from which ceramic materials are made.  They may be water filter materials such as sand, diatomaceous earth, or magnesia.  It may be a food additive such as silica, diatomaceous earth, calcium carbonate, sodium metasilicate, sodium metabisulfite, sodium tripolyphosphate, or monocalcium phosphate.  They may be ingredients for concrete, mortar, grout, plaster, or dry wall.  Or they may be a component of a separation column or of a chemical sensor.  The material may be a component of a corrosion resistant primer coating or drying agent.  It may also be a fire retardant such as aluminum trihydrate or antimony oxide.

XPS Analysis:

  • Particle surface chemistry complete with quantitative elemental composition and chemical phase analysis of multiple complex phases, see the example of a complex, 3-chemical phase feldspar
  • Differentiate surface chemistry with interior chemistry by analyzing as-received materials compared to freshly ground particles of material or by argon ion sputtering
  • Great sensitivity to a very thin surface chemistry affecting particle bonding in a polymer matrix or agglomeration control surface treatments
  • Used to determine and measure the degree of surface hydration
  • Sometimes used to examine fill materials added to polymers following burn-off of the resin by TGA or other means

Themogravimetry or TGA Analysis:

  • Determine decomposition temperature
  • Determine weight loss, which provides the amount of decomposing material, measuring loss of water from hydrated materials or carbon dioxide from a carbonate, for instance
  • Impurity detection and measurement
  • Measure absorbed water or other solvent weight
  • Determine the composition of some thermally decomposable materials such as the amount of silver carbonate in a silver oxide

Differential Scanning Calorimetry or DSC Analysis:

  • Determine melting temperature and heat of fusion
  • Determine energy and temperature of reaction between an inorganic material and another material
  • Impurity detection and measurement by measuring the latent heat of melting or looking for an internal reaction upon heating
  • Measure energy to desorb water or to decompose
  • Measure temperature of a phase transition

Thermomechanical or TMA Analysis:

  • Determine CTE or thermal expansion of materials in plate or cylindrical forms
  • Determine temperature of a phase change

SEM/EDX Analysis:

  • Determine surface morphology and shapes of particles
  • Determine particle sizes
  • Map the distribution of elements or examine a particle or area for its elemental composition for carbon and heavier elements

FTIR Analysis:

  • Offers quick determination of whether carbonates, phosphates, nitrates, nitrites, numerous minerals, or water are present with relative quantitative measurement
  • Measures organic surface coatings and treatments to a 1 to 2 μm depth
  • Detect variations in an organic coating thickness over a different organic substrate material

Optical Microscopy:

  • Determine the size and shape of particles
  • Use color differences to indicate different chemical phases and their locations
  • Select typical or atypical areas for further analysis by other techniques
  • Document the microscopic appearance associated with a spectrum obtained by another analytical technique

Electrochemistry:

  • Measure corrosion rates of soluble salts on metals and metal alloys

ASTM Test Methods:

  • ASTM E793 – Standard Test Method for Enthalpies of Fusion and Crystallization by Differential Scanning Calorimetry
  • ASTM E794 – Standard Test Method for Melting and Crystallization Temperatures by Thermal Analysis
  • ASTM E1131 – Standard Test Method for Compositional Analysis by Thermogravimetry