Methyl Isobutyl Carbinol (MIBC) CAS 108-11-2

What Is Methyl Isobutyl Carbinol (MIBC)?

Methyl Isobutyl Carbinol, commonly abbreviated as MIBC, is a colorless liquid secondary alcohol primarily used as a frother in mineral flotation. Its systematic chemical name is 4-methylpentan-2-ol.

MIBC helps generate and control air bubbles in flotation pulp, allowing hydrophobic mineral particles to attach to the bubbles and move into the froth phase. It is widely used in the beneficiation of copper, molybdenum, lead-zinc and other sulfide ores, as well as in selected coal flotation processes.

MIBC is also used as an industrial solvent and as an intermediate in the production of lubricant additives and other specialty chemicals.

MIBC Quick Facts

Actual sales specifications and physical-property values must be confirmed against the applicable AOZUN Technical Data Sheet, Certificate of Analysis and Safety Data Sheet.

How Does MIBC Work as a Flotation Frother?

In froth flotation, MIBC adsorbs at the air-water interface and helps control bubble formation and coalescence. The resulting bubble population carries hydrophobic mineral particles from the slurry into the froth layer, where the mineral-rich concentrate can be collected.

What MIBC Does—and Does Not Do

MIBC is a frother. Its main role is to influence:

• Bubble size

• Bubble coalescence

• Froth texture

• Froth mobility

• Froth drainage

• Froth breakage

• Mineral-carrying capacity

MIBC is not normally the collector responsible for making a mineral surface hydrophobic. Collectors, frothers and modifiers perform different functions and should not be treated as interchangeable reagents.

MIBC is also not a defoamer. A defoamer is intended to destroy or suppress foam, while MIBC is added to create and control froth during flotation.

Why Is MIBC Used in Mineral Flotation?

MIBC is valued because it can produce a relatively fine, mobile and readily breakable froth under suitable operating conditions.

Potential operational benefits include:

• Controlled bubble formation

• Relatively fast flotation kinetics

• Good froth mobility

• Reduced risk of excessively persistent froth

• Easier concentrate handling

• Compatibility with many collector systems

• Consistent performance when reagent quality is controlled

Actual recovery and grade depend on the complete ore-reagent system. MIBC alone cannot compensate for unsuitable grinding, poor liberation, incorrect collector selection or unstable plant operation.

Typical MIBC Specifications

The following values are reference purchasing parameters based on common commercial MIBC specifications. They are not a guaranteed AOZUN specification unless confirmed in the quotation and sales contract.

Buyers should state the required specification, test methods and acceptance criteria when requesting a quotation.

What Do the Main MIBC Quality Parameters Mean?

Purity

Purity indicates the percentage of MIBC measured by gas chromatography. Changes in purity or organic impurity profile may affect froth behavior, odor, evaporation and process repeatability.

Water Content

Excessive water changes the amount of active MIBC delivered per unit mass and may affect storage, metering and process consistency. Water is commonly measured using a Karl Fischer method.

Acidity

Acidity is generally reported as acetic acid. A low acidity limit helps control corrosion risk and confirms product consistency.

Color

MIBC is normally a clear, colorless liquid. Elevated APHA color may indicate contamination, degradation or differences in the manufacturing and storage history.

Ketones and Organic Impurities

Residual ketones and other organic impurities can affect odor, solvency, volatility and flotation response. Buyers with sensitive operations may request a defined impurity profile.

Density

Density is useful for incoming inspection, storage-tank inventory calculations and conversion between mass and volume.

Distillation Range

The distillation range provides information about product identity, volatility and the presence of lower- or higher-boiling impurities.

Nonvolatile Matter

Low nonvolatile residue helps reduce contamination and deposits in tanks, metering systems and downstream processes.

MIBC Applications

Copper and Molybdenum Flotation

MIBC is widely used in flotation circuits processing copper and molybdenum sulfide ores. It is normally applied with collectors and appropriate modifiers to develop a manageable froth and support the recovery of hydrophobic mineral particles.

Lead-Zinc and Polymetallic Ores

In lead-zinc and other polymetallic flotation circuits, MIBC may be used where a relatively mobile and less persistent froth is desired.

Because selectivity depends on mineralogy, grinding, pH, collector chemistry and water quality, laboratory testing should precede plant-scale changes.

Coal Flotation

MIBC can be used in selected fine-coal flotation systems. It helps control bubble and froth characteristics, while hydrocarbon collectors or other reagents provide the required hydrophobicity.

Gold-Bearing and Other Sulfide Ores

MIBC may be incorporated into flotation circuits treating gold-bearing sulfides and other valuable minerals. Suitability should be determined through mineralogical analysis and flotation testing.

Industrial Solvent

MIBC has limited water solubility but is miscible with many organic solvents. It may be used as a solvent or cosolvent for:

• Resins

• Waxes

• Oils

• Dyes

• Nitrocellulose

• Ethyl cellulose

• Selected coatings and inks

Formulators must evaluate evaporation rate, solvency, flash point and compatibility with the complete formulation.

Lubricant-Additive Intermediate

MIBC can be used as an intermediate in the production of selected lubricant additives, including certain zinc dialkyldithiophosphate systems.

Specialty Chemical Manufacturing

Other potential uses include selected brake-fluid components, corrosion-inhibitor intermediates, plasticizer precursors and specialty organic synthesis.

Suitability for any synthesis must be confirmed through process development and regulatory review.

MIBC vs Collectors, Modifiers and Defoamers

The best flotation result comes from balancing these reagent functions rather than increasing only the frother dosage.

MIBC vs Pine Oil Frother

MIBC and pine oil can both be used as flotation frothers, but they do not necessarily produce the same froth structure.

Neither product is universally superior. The correct choice depends on mineralogy, particle size, collector system, water chemistry and required froth behavior.

MIBC vs Polyglycol Frothers

Polyglycol frothers often generate more persistent froths than short-chain alcohol frothers such as MIBC. This may be helpful in some circuits but can create problems in others.

MIBC may be preferred when operators require:

• Rapid froth breakage

• Easier concentrate pumping

• Lower froth persistence

• Fast response to dosage changes

• Cleaner phase separation

A blend of alcohol and polyglycol frothers may also be evaluated when neither material alone provides the required froth profile.

How Should MIBC Dosage Be Determined?

There is no universal MIBC dosage for every ore or flotation plant. Dosage is commonly expressed as grams per tonne of ore, milliliters per minute or concentration in the reagent solution.

The optimum dosage depends on:

• Ore mineralogy

• Valuable-mineral liberation

• Particle-size distribution

• Solids concentration

• Airflow

• Cell design

• Impeller speed

• Pulp pH

• Water quality

• Collector dosage

• Depressant and activator selection

• Required concentrate grade and recovery

Too little MIBC may produce unstable froth and poor mineral transport. Too much may create excessive froth volume, increased water recovery, entrainment of fine gangue or reduced selectivity.

Bench testing, locked-cycle testing and controlled plant trials should be used to establish the operating range.

Which Flotation Variables Should Be Monitored?

When evaluating MIBC performance, monitor more than concentrate recovery alone.

Useful indicators include:

• Bubble size

• Froth height

• Froth mobility

• Froth persistence

• Froth drainage

• Air recovery

• Concentrate mass pull

• Water recovery

• Valuable-mineral recovery

• Concentrate grade

• Gangue entrainment

• Reagent consumption

• Downstream concentrate handling

A change that increases recovery but significantly reduces concentrate grade may not improve total plant economics.

How Should MIBC Be Added to a Flotation Circuit?

MIBC may be metered directly or introduced through a properly designed reagent-distribution system.

Important considerations include:

• Accurate low-flow metering

• Stable feed pressure

• Compatible pump and seal materials

• Appropriate injection location

• Sufficient mixing before flotation

• Prevention of leaks and vapor accumulation

• Calibration of flowmeters and dosing pumps

• Grounding and bonding of equipment

• Explosion-protected electrical equipment where required

Plant personnel should follow the equipment manufacturer’s recommendations and the current SDS.

MIBC Solubility and Formulation Considerations

MIBC has limited solubility in water, commonly reported at approximately 15–20 g/L at room temperature. It is miscible with many common organic solvents.

Its limited water solubility is one reason accurate dosing and mixing are important. Concentrated MIBC should not be assumed to disperse instantly or uniformly in every process stream.

Before preparing a diluted reagent system, confirm:

• Water temperature

• Water hardness

• Mixing intensity

• Required concentration

• Solution stability

• Pump compatibility

• Tank ventilation

• Fire-control requirements

Do not mix MIBC with an unidentified reagent or strong oxidizing material.

How to Evaluate an MIBC Supplier

A reliable MIBC supplier should provide more than a quoted purity value.

Buyers should evaluate:

1. Product identity and CAS number

2. Purity and impurity profile

3. Water-content limit

4. Acidity

5. Color

6. Density

7. Distillation range

8. Batch-to-batch consistency

9. COA and test methods

10. SDS and transport classification

11. Packaging condition

12. Tank, drum or IBC availability

13. Export-document capability

14. Batch traceability

15. Change-notification procedure

16. Sample and pre-shipment inspection options

A flotation trial should use material representative of the intended commercial supply.

Recommended Incoming Quality Checks

Depending on the application and purchasing agreement, incoming MIBC may be checked for:

• Container and seal condition

• Product labeling

• Batch number

• Appearance

• Odor

• Purity by GC

• Water by Karl Fischer titration

• Density

• Acidity

• APHA color

• Distillation range

• COA compliance

Retain samples can help investigate unexpected changes in plant flotation performance.

MIBC Packaging Options

MIBC may be supplied in:

• Steel drums

• IBCs

• ISO tank containers

• Bulk tank trucks

• Other approved dangerous-goods packaging

Available package size, net weight, pallet configuration and container type should be confirmed in the quotation.

Packaging must be compatible with flammable liquids and meet the applicable transport regulations.

MIBC Storage and Handling

Store MIBC in a cool, dry and well-ventilated area away from heat, hot surfaces, sparks, flames and other ignition sources.

Recommended precautions include:

• Keep containers tightly closed.

• Ground and bond containers and transfer equipment.

• Use explosion-protected equipment where required.

• Use non-sparking tools.

• Prevent static-electricity accumulation.

• Avoid breathing vapor or mist.

• Wear suitable gloves and eye protection.

• Prevent contact with strong oxidizing agents.

• Do not store near food or animal feed.

• Control access to trained personnel.

• Follow the current SDS and local fire code.

Vapors may travel to an ignition source and flash back. Ventilation and ignition control are therefore essential during storage and transfer.

MIBC Safety Information

MIBC is generally classified as a flammable liquid and vapor. It can cause serious eye irritation and may cause respiratory irritation.

Potential symptoms of excessive vapor exposure may include:

• Headache

• Dizziness

• Tiredness

• Nausea

• Respiratory discomfort

Use the product only in an adequately ventilated industrial environment. PPE, exposure controls and emergency procedures must be selected according to the current SDS and workplace risk assessment.

MIBC is an industrial chemical. It is not intended for food, pharmaceutical, pesticide or household use unless a separately qualified product and applicable authorization exist.

MIBC Transport Information

A commonly referenced transport classification is:

Transport classification must be verified against the shipment-specific SDS, product composition, package size, transport mode and destination-country regulations.

Do not use a generic UN 1993 classification when the substance-specific UN 2053 entry applies, unless a qualified dangerous-goods assessment determines otherwise.

What Documents Should an MIBC Supplier Provide?

Depending on the order and destination, buyers may request:

• Certificate of Analysis

• Safety Data Sheet

• Technical Data Sheet

• Product specification

• Commercial invoice

• Packing list

• Certificate of Origin

• Dangerous-goods declaration

• Transport classification

• Export documentation

• Inspection report

• Regulatory-status declaration

The product name, CAS number, batch number and packaging information should be consistent across all documents.

Why Source MIBC from AOZUN?

AOZUN supports industrial buyers seeking MIBC for mineral flotation and other qualified industrial applications.

Available commercial support may include:

• Specification review

• Batch-specific COA

• SDS and transport documentation

• Drum, IBC or bulk packaging discussion

• Sample evaluation

• Export-document coordination

• International shipment planning

• Pre-shipment inspection arrangements

• Technical communication during supplier qualification

Product specifications, availability, packaging and delivery schedule should be confirmed in the final quotation and sales contract.

Information to Include in Your MIBC RFQ

For a more accurate quotation, provide:

• Product name: MIBC

• CAS number: 108-11-2

• Required purity

• Water-content limit

• Acidity limit

• Required impurity controls

• Intended application

• Ore type, if used for flotation

• Trial or commercial quantity

• Packaging requirement

• Destination port or address

• Required documents

• Target delivery date

• Sample requirement

If you are replacing an existing MIBC supplier, include the current specification or a representative COA for comparison.

Frequently Asked Questions

What is MIBC?

MIBC is methyl isobutyl carbinol, also known as 4-methylpentan-2-ol. It is a secondary alcohol primarily used as a frother in mineral flotation.

What is the CAS number of MIBC?

The CAS number of MIBC is 108-11-2.

What is the molecular formula of MIBC?

Its molecular formula is C₆H₁₄O, and its molecular weight is 102.17 g/mol.

What is MIBC used for in mining?

MIBC controls bubble formation and froth characteristics during mineral flotation. It is used in selected copper, molybdenum, lead-zinc, coal and other flotation circuits.

Is MIBC a collector?

No. MIBC is primarily a frother. Collectors make selected mineral surfaces hydrophobic, while MIBC controls bubbles and froth behavior.

Is MIBC a defoamer?

No. MIBC promotes and controls flotation froth. A defoamer suppresses or destroys foam.

Is MIBC soluble in water?

MIBC has limited water solubility, commonly reported at approximately 15–20 g/L at room temperature. It is miscible with many organic solvents.

What purity is commonly supplied?

Commercial MIBC is commonly supplied at a minimum purity of 99.0%, although the contracted specification must be confirmed with the supplier.

What is the typical MIBC density?

Commercial specifications commonly report a density of approximately 0.805–0.810 g/cm³ at 20°C.

Is MIBC flammable?

Yes. MIBC is a flammable liquid and vapor. It must be protected from heat, sparks, flames, static discharge and other ignition sources.

What is the UN number for MIBC?

MIBC is commonly transported under UN 2053, Class 3, Packing Group III. Always confirm the shipment-specific classification using the current SDS.

Is MIBC better than pine oil?

Neither frother is universally better. MIBC often produces a more consistent, mobile and readily breakable froth, while pine oil may produce a more persistent froth in some circuits. Ore testing is required.

Can AOZUN provide an MIBC sample?

Sample availability can be discussed during the quotation process. Provide your application, required specification, quantity and destination when submitting the request.

Request an MIBC Quote

Contact AOZUN for Methyl Isobutyl Carbinol pricing, specifications, packaging and export information.

Send us your required purity, quantity, application, packaging, destination and delivery schedule. Our team will review the requirement and confirm the appropriate specification and commercial terms.