Method and apparatus for measuring the concentration of water, iron and aluminum in iron ore by neutron radiation

Claim 3

A method as claimed in claim 1, in which the material is iron ore, the specific component is iron, the neutrons irradiatIng the material are slow neutrons, and the measurement of gamma radiation is effected at substantially the time of irradiation.

Claim 4

A method as claimed in claim 1, in which the specific component is aluminium, the neutrons irradiating the material are slow neutrons, and the measurement of gamma radiation is effected within about the half-life of the excited aluminium nucleus produced by the irradiation of the material.

Claim 5

A method as claimed in claim 3, in which the material which is irradiated is iron ore.

Claim 6

A method as claimed in claim 1, in which the number of gamma rays characteristic of at least one further specific component of the material emitted per unit time from the material is measured and correlated with known values of the number of gamma rays characteristic of the further specific component or components obtained from samples of the material having known concentrations of the further specific component or components to determine the concentration of the further specific component or components in the material being examined.

Claim 7

A method as claimed in claim 5, in which the material is iron ore, and gamma rays characteristic of iron and aluminium are measured, the measurement of the gamma radiation characteristic of aluminium being effected within about the half-life of an excited aluminium nucleus.

Claim 8

A method as claimed in claim 1 in which the material is being transported on a conveyor belt at the time of measurement.

Claim 9

A method as claimed in claim 7, including the additional step of measuring the depth or weight of the material on the conveyor belt and using the measured value of depth or weight so obtained to modify the correlation of measured parameters with known values of those parameters obtained for samples of the material having known specific component and water concentrations.

Claim 10

A method as claimed in claim 8, in which the measured values of water and specific component concentrations are utilised to control the distribution of the material from the conveyor belt.

Claim 11

A method as claimed in claim 1, in which the material is the rock in the immediate vicinity of a borehole.

Claim 12

A method as claimed in claim 10, including, in addition, measurement of the density of the rock in the immediate vicinity of the borehole and measurement of the diameter of the borehole, and using the additional measurement to modify the correlation of measured parameters with known values of those parameters obtained from samples of the material having known specific component and water concentrations.

Claim 13

Apparatus for quantitative measurement of the concentration of water and a specific component in a material comprising: i. a source of neutrons for irradiating the material, ii. a neutron detector positioned to monitor the neutron population in the vicinity of the irradiated material at the time of irradiation thereof, iii. a gamma ray detector designed to produce an output signal indicative of the number of gamma rays received from the irradiated material which have an energy within a predetermined energy range characteristic of the decay of an excited nucleus of the specific component, and iv. counting circuits to which the outputs of said detectors are respectively connected, the outputs from which are fed to calculating devices which are programmed to measure the differences between (a) the measured neutron flux and number of gamma rays and (b) known values of these parameters obtained from samples of the material having known concentrations of water and the specific component and, from the difference measurements to determine the concentration of water and the specific component in the material being examined.

Claim 14

Apparatus for quantitative measurement of the concentration of water and a specific component in a material comprising: i. a source of neutrons for irradiating the material, ii. a neutron detector positioned to monitor the neutron population in the vicinity of the irradiated material at the time of irradiation thereof, iii. a gamma ray detector designed to produce an output signal indicative of the number of gamma rays received from the irradiated material which have an energy within a predetermined energy range characteristic of the decay of an excited nucleus of the specific component, and iv. counting circuits to which the outputs of said detectors are respectively connected, the outputs from which are fed to calculating devices which are programmed to measure the differences between (a) the measured neutron flux and number of gamma rays and (b) known values of these parameters obtained from samples of the material having known concentrations of water and the specific component and, from the difference measurements to determine the concentration of water and the specific component in the material being examined.

Claim 15

Apparatus as claimed in claim 12, including a second gamma ray detector designed to produce an output signal indicative of the number of gamma rays received from the irradiated material which have an energy within a predetermined energy range characteristic of the decay of an excited nucleus of a second Specific component of the material, the output of the second gamma ray detector being connected to a respective counting circuit, the output of which is fed, together with the output of the counting device associated with the neutron detector, to a further calculating device programmed to correlate the outputs fed thereto with known values of the number of gamma rays characteristic of the second specific component obtained from samples of the material having known concentrations of the second specific component.

Claim 16

apparatus as claimed in claim 12, in which the material is located on a conveyor belt which moves past the detectors, said apparatus including means to measure the depth of mass of material which is being irradiated, said depth or mass measuring means providing a signal which is fed to each calculating device for use in the determination of the concentration of water and specific component.

Claim 17

Apparatus as claimed in claim 12, in which the material is located on a conveyor belt which moves past the detectors, the neutron source produces slow neutrons, the material is iron ore, the first and second specific components are iron and aluminum, respectively, and the second gamma ray detector is located downstream of the point of irradiation of the material a distance corresponding to the distance moved by the material in about the half-life of an excited aluminium nucleus.

Claim 18

Apparatus as claimed in claim 12, in which the material is the rock in the immediate vicinity of a borehole and the apparatus is mounted on a borehole probe.

Claim 19

Apparatus as claimed in any one of claim 12, in which the counting circuits are ratemeters and the calculating devices are analogue adders.

Claim 20

Apparatus as claimed in any one of claim 12, in which the counting circuits are channels in a multi-channel analyser or digital counters, and the calculating devices are digital.