Adsorbents / Absorbents
Humic acids exhibit some novel surface and pore characteristics. They are a relatively high surface area material, organophilic and exhibit certain types of reactive sites such as phenolic hydroxyl groups, carboxylic acid groups and have the ability to adsorb, absorb and selectively extract various organic materials as well as some inorganic compounds. Due to these properties, they can be used in special filter media, selective extractants and chromatographic substances. They can be used for removing trace amounts of nonaqueous liquids such as oils from aqueous streams. They can also be utilized in the removal of trace contaminants from aqueous streams.
Asphalt / Bitumen
Humic acids can be used in modifying asphalt based products such as roofing compounds, mastics, sealants, coatings, etc. Due to their dispersant characteristics, they have the potential of improving the loading of inert solids. They also have potential use as crack-resistant agents, flow control additives, sag resistant agents, spray modifiers, adhesion modifiers, enhancer or inert fillers and as agents to control penetration and evaporation of asphalt solvents. Humic acids help to stabilize certain types of asphalt based undercoatings and soundproofing compounds. They also assist in improving the aging characteristics and the thermal stability of asphalt based systems.
Humic acids are used as expanders in lead accumulators in the battery industry. As surface active materials, they influence the size and morphology of lead and leadsulphate during the charging and discharging cycles and produce an increase in charge potential of the lead accumulator as well as the discharging capacity and lead to a reduction in self-discharge of the battery and thus prolong its life.
Humic acids have been traditionally used in ceramics as liquefier and dispersant agents. Whereas in the past humic acids were used also as liquefiers for glazes, presently the usage is limited to liquefying and diluting ceramic masses. Ceramic masses, that are prepared in fluid state, need liquefier agents, in order to optimize the rheological behaviour of the produced mud. A high hard-material concentration is aimed in order to keep the energy costs for drying low and to reach high densities. As liquefier agent, humic acids influence the viscosity, rheology, pH-value of the masses directly and streaks, crack-resistance and absorption time indirectly.
Controlled Release Agents
Due to their high, porous and hydrophobic surface area, humic acids can be used in controlled release applications, where it is important to adsorb, absorb and release products at controlled rates.
Due to their surface area and hydrophobic nature, humic acids can be used as solid or liquid defoamers where dark colour is not a problem.
Foundries & Green Sand Systems
Humic acids can be used as foundry sand additives because of their dispersant properties and binding characteristics both in oil base and water base foundry sands. Humic acids block electrostatic interaction and thus makes the clay unwettable in sand systems. They reduce clay viscosity, improve muller efficiency and increase mold permeability. They also absorb and retain water and improve foundry environment. Use of humic acids in foundries and green sand systems as an additive improves flowability and clay efficiency and may result in the reduced use of clay in the sand system, saving costs considerably in the long run.
Grease & Lubricants
Due to their organophilic nature and stability even in high temperatures, humic acids can be used as a special additive for modifying the gel structure and other properties of soap and organoclay based greases and lubricants. A higher purity and finer grind of product can be attained through the use of humic acids.
Immobilization of Enzymes
Humic acids can be used for the immobilization of certain types of enzymes due to their hydrophobic and potentially reactive surfaces.
Paints & Industrial Coatings
Humic acids can be used as black tinting agents, special pigments and rheological control additives in oil base paints, industrial coatings, varnishes and shellacs. They can especially be utilized in colouring wood, leather and carpets.
Pharmaceuticals & Cosmetics
Humic acids can change the activities of enzymes, for instance in the skin. Humic acids are traditionally used in the pharma industry in the preparation of bath salts and artificial mud-bath. Produced in combination with different preservatives, products containing humic acids are applied in particular for the treatment of rheumatic and gynaecological diseases. They also have potential usage in cancer treatment.
Humic acids can be applied for modifying the rheological properties in black or dark coloured printing inks. They exhibit dispersant properties (flow control) in certain types of solvent based systems. They can be used as colloidal tinting agents/pigments due to the black colour. An important property of humic acids is their ability to limit penetration of certain oils into porous substrates. This is especially applicable for certain types of ink formulations for paper and ribbon.
Humic acids can be used in the compounding and proccessing of rubber. Due to their organophilic and non-gelling colloidal structure, some suggested usages are as fillers/extenders, tinting compounds, property modifiers (elascticity, impact resistance, anti-cracking/crazing, aging, UV modifier, etc.), special anti-oxidants, reactive fillers or modifiers in certain systems, pigment dispersants and plasticizer modification through cross-linking reactions.