Sex without any consent with a slave woman by her owner was so obvious in Islamic literature that none of the Islamic scholars even thought it was necessary to indulge in the discussion if the owner needed the consent of slave women before having sex with her or not. 

Unfortunately, modern Islamic apologists deem it Halal to deceive people and to tell open lies to defend Islam. They are denying 14 centuries-long history of Islamic slavery, where millions of poor slave girls were raped without any consent. 

An Islamic apologist wrote:

 A Muslim judge Abū ‘Abdullāh al-Ḥalīmī (d. 1012 CE) explicitly prohibit even touching female slaves without their consent:

وإن اشترى جارية فكرهت أن يمسها أو يضاجعها فلا يمسها ولا يضاجعها ولا يطأها إلا بإذنها

“If a female slave is purchased and she dislikes to be touched, or slept with, then he may not touch her, lie with her, or have intercourse with her unless she consents.” (Minhāj fī Shu’ab al-Imān 3/267)

Reply:

If you are to read the original book (https://shamela.ws/book/18567/1353) in full, this particular line as written by Al Haleemi is a recommendation, not an obligation. He was making many recommendations to develop good relations with slaves, and it is one of them. Thus, it has nothing to do with obligation in Sharia. 

Hammering the point home even further, in 3/312, this Muslim judge Al Haleemi mentions that the master can force his pagan slaves to convert to Islam, with one of the given reasons being that it makes his female slaves permissible for him [وإنما ذكرت هذه المسألة رواية في الأمة الوثنية. فقد يجوز أن يكون فيها خاصة دون العبد. لأنه لا يمكن سيدها الاستمتاع بها مع وثنيتها، فيجبر بها على الإسلام، ليتمكن من الاستمتاع، كما يجبر الرجل امرأته الذمية على الغسل من الحيض لتهيأ له مباشرتها. والعبد مفارق ذلك للامة، أن توثنه لا يمنع سيده من الاستمتاع به في شيء.]. Thus, it strains logic to suggest that he can force his slave to convert to Islam for the sake of having sex with her but for some reason cannot have sex with her against her consent.

Compared to this singular recommendation of this Muslim judge Al Haleemi, there are dozens of clear proofs in Ahadith and history and Islamic Jurisprudence, where the companions raped the captive women and even minor girls. 

Muhammad allowed his Jihadists to have sex with captive women even when their husbands were alive. That is rape. 

Sahih Muslim (link):

باب جَوَازِ وَطْءِ الْمَسْبِيَّةِ بَعْدَ الاِسْتِبْرَاءِ وَإِنْ كَانَ لَهَا زَوْجٌ انْفَسَخَ نِكَاحُهَا بِالسَّبْي

Chapter: It is permissible to have intercourse with a female captive after it is established that she is not pregnant, and if she has a husband, then her marriage is annulled when she is captured
عَنْ أَبِي سَعِيدٍ، الْخُدْرِيِّ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم يَوْمَ حُنَيْنٍ بَعَثَ جَيْشًا إِلَى أَوْطَاسٍ فَلَقُوا عَدُوًّا فَقَاتَلُوهُمْ فَظَهَرُوا عَلَيْهِمْ وَأَصَابُوا لَهُمْ سَبَايَا فَكَأَنَّ نَاسًا مِنْ أَصْحَابِ رَسُولِ اللَّهِ صلى الله عليه وسلم تَحَرَّجُوا مِنْ غِشْيَانِهِنَّ مِنْ أَجْلِ أَزْوَاجِهِنَّ مِنَ الْمُشْرِكِينَ فَأَنْزَلَ اللَّهُ عَزَّ وَجَلَّ فِي ذَلِكَ ‏{‏ وَالْمُحْصَنَاتُ مِنَ النِّسَاءِ إِلاَّ مَا مَلَكَتْ أَيْمَانُكُمْ‏}‏ أَىْ فَهُنَّ لَكُمْ حَلاَلٌ إِذَا انْقَضَتْ عِدَّتُهُنَّ ‏.
Abu Sa'id al-Khudri (Allah her pleased with him) reported that at the Battle of Hanain Allah's Messenger sent an army to Autas and encountered the enemy and fought with them. Having overcome them and taken them captives, the Companions of Allah's Messenger seemed to refrain from having intercourse with captive women because of their husbands being polytheists. Then Allah, Most High, sent down regarding that:" And women already married, except those whom your right hands possess (iv. 24)"

Moreover, please also read Kecia Ali's response to this lie: Concubinage and Consent

And Imam Shafi'i wrote in this book Al-Umm:

وله أن يزوج أمته بغير إذنها بكرا كانت أو ثيبا

“He (i.e. the owner) may marry off his female slave without her consent whether she is a virgin or non-virgin.

Ande here is a Fatwa. Translation for those who can't read Arabic (Credit: User afiefh from Reddit):

Question: If a right hand possession (female slave) refuses to have sex with her master, is it permissible to compel her by force?

Answer: Praise be to Allah, and may prayers and peace be upon the Messenger of God and his family and companions. It is better for a Muslim to occupy himself with what concerns him of the rulings of his religion, and to invest his time and energy in seeking knowledge that will benefit him. The meaning of knowledge is action. Knowledge that does not facilitate action, it is not good to search for. Among that are issues related to the ownership what the right hand possess (slaves); There is no use for it in this era.

With regard to the question: If the wife is not permitted to refrain from intimate relations with her husband except with a valid excuse, then it is more so not permissible for the right hand possession to refrain from intimate relations with her master except with a valid excuse; he has more right to sex with her through possessing her than the man having intercourse with his wife through the marriage contract; Because the ownership of the right hand possession is complete ownership, so he owns all her benefits, while marriage contracts only grant him only the ownership intended through the marriage contract so it is a restricted form of ownership.

If the wife or the right hand possession refuses to have sex without a legitimate excuse, then the husband or the master may force her to do so. However, he should take into account her psychological state, and treat her kindly. Kindness in all matters is desirable, as the prophet, may God’s prayers and peace be upon him, said: “Kindness is not found in anything but that it beautifies it, and it is not removed from anything except that it disgraces it.” (Narrated by Muslim).

Allah knows best.

And also see this:

C. Baugh “Minor Marriage in Early Islamic Law” p 10, footnote 45.45:

Almost invariably, as jurists consider the legal parameters of sex with prepubescents, (“at what point is the minor female able to tolerate the sexual act upon her”/matā tuṣliḥ lilwaṭʾ) the word used when describing sexual relations with a prepubescent female is waṭʾ. This is a word that I have chosen to translate as “to perform the sexual act upon her.” This translation, although unwieldy, seems to convey the lack of mutuality in the sexual act that this word suggests (unlike, for example, the word jimāʿ ). It is worth noting that the semantic range of the word includes “to tread/step on;” indeed this is given as the primary meaning of the word. See Ibn Manẓūr, Lisān al-‘Arab (Beirut: Dār Ṣādir, 1955), 2:195–197.

And also see this: 

Slavery and Islam, (2019), Jonathan A.C. Brown, Oneworld Publications ISBN 978-1-78607-635-9, p. 372-373/589:

“Even among medieval Jewish and Christian communities, for whom slavery was uncontroversial, the Muslim practice of slave-concubinage was outrageous” and on p380 “But it was a greatly diminished autonomy. In the Shariah, consent was crucial if you belonged to a class of individuals whose consent mattered: free women and men who were adults (even male slaves could not be married off against their will according to the Hanbali and Shafi ʿ i schools, and this extended to slaves with mukataba arrangements in the Hanafi school). 47 Consent did not matter for minors. And it did not matter for female slaves, who sexual relationship with them if he wanted (provided the woman was not married or under a contract to buy her own freedom)”

Misquoting al-Shafi'i to prove CONSENT:

Islamic apologists present the following excuse (link):

Imam Al Shaafi'i said:

وإذا اغتصب الرجل الجارية ثم وطئها بعد الغصب وهو من غير أهل الجهالة أخذت منه الجارية والعقر وأقيم عليه حد الزنا

"If a man acquires by force a slave-girl, then has sexual intercourse with her after he acquires her by force, and if he is not excused by ignorance, then the slave-girl will be taken from him, he is required to pay the fine, and he will receive the punishment for illegal sexual intercourse." (Imam Al Shaafi'i, Kitaabul Umm, Volume 3, page 253)

It is a clear deception while Shafi'i is not talking about the owner having sex with his own slave girl, but it is about kidnapping and then raping the slave girl of another person

Misquoting Imam Malik to prove CONSENT:

The dishonesty of Islamic apologists continues. They use the following tradition by Imam Malik to prove an owner needs consent from his female slave before having sex with her (link):

Imam Maalik said: 

الأمر عندنا في الرجل يغتصب المرأة بكراً كانت أو ثيبا : أنها إن كانت حرة : فعليه صداق مثلها , وإن كانت أمَة : فعليه ما نقص من ثمنها ، والعقوبة في ذلك على المغتصب ، ولا عقوبة على المغتصبة في ذلك كله

In our view the man who rapes a woman, regardless of whether she is a virgin or not, if she is a free woman he must pay a "dowry" like that of her peers, and if she is a slave he must pay whatever has been detracted from her value. The punishment is to be carried out on the rapist and there is no punishment for the woman who has been raped, whatever the case.  (Imam Maalik, Al-Muwatta', Volume 2, page 734)

Once again, just like in the case of Shafi'i above, here Malik is not talking about an owner raping his OWN slave woman, but he is only talking about raping the slave woman of another person

Misquoting the tradition of Dharar to prove CONSENT:

Islamic apologists also use the following tradition to prove that an owner needs the consent of his slave girl before having sex with her (link):

Sunan Al Bayhaqi, Volume 2, page 363, Hadith no. 18685:  

Abu al-Hussain bin al-Fadhl al-Qatan narrated from Abdullah bin Jaffar bin Darestweh from Yaqub bin Sufyan from al-Hassab bin Rabee from Abdullah bin al-Mubarak from Kahmas from Harun bin Al-Asam who said: Umar bin al-Khatab may Allah be pleased with him sent Khalid bin al-Walid in an army, hence Khalid sent Dharar bin al-Auwzwar in a squadron and they invaded a district belonging to the tribe of Bani Asad. They then captured a pretty bride, Dharar liked her hence he asked his companions to grant her to him and they did so. He then had sexual intercourse with her, when he completed his mission he felt guilty, and went to Khalid and told him about what he did. Khalid said: 'I permit you and made it lawful to you.' He said: 'No not until you write a message to Umar'. (Then they sent a message to Umar) and Umar answered that he (Dharar) should be stoned. By the time Umar's message was delivered, Dharar was dead. (Khalid) said: 'Allah didn't want to disgrace Dharar'

Again, it is clear that he was punished by Umar because he raped that slave girl before becoming his owner (i.e. before the distribution of war booty). 

This is the same if you have sex with a free woman but do Nikah afterwards (i.e. you are not a husband and wife at the time of sex). Due to it, even if you marry later, still you will be punished for fornication. 

In simple words, this tradition has nothing to do with an owner having sex with his own slave woman without her consent. 

Misquoting al-Shafi'i agin to prove CONSENT:

Islamic apologists also misquote al-Shafi'i again to prove an owner needs consent from his slave woman before having sex with her (link):

وَهَكَذَا لَوْ كَانَتْ مُنْفَرِدَةً بِهِ أَوْ مَعَ أَمَةٍ لَهُ يَطَؤُهَا أُمِرَ بِتَقْوَى اللَّهِ تَعَالَى وَأَنْ لَا يضربهَا فِي الْجِمَاعِ وَلَمْ يُفْرَضْ عَلَيْهِمِنْهُ شَيْءٌ بِعَيْنِهِ إنَّمَا يُفْرَضُ عَلَيْهِ مَا لَا صَلَاحَ لَهَا إلَّا بِهِ مِنْ نَفَقَةٍ وَسُكْنَى وَكِسْوَةٍ وَأَنْ يَأْوِيَ إلَيْهَا فَأَمَّا الْجِمَاعُ فَمَوْضِعُ تَلَذُّذٍ وَلَا يُجْبَرُ أَحَدٌ عَلَيْهِ

He said: And so if she is alone with him [i.e., he has no other wives], or with a slavegirl he has that he has sex with, he is ordered [to fulfill his obligations] in reverence to God the Exalted, and not to do her harm with regard to intercourse, and he is not obligated to any specific amount of it (wa lam yufraḍ ʿalayhi minhu shayʾbi ʿaynihi). Rather, he is only [obligated] to provide what she absolutely cannot do without, maintenance and lodging and clothing, and also to visit her (yaʾwī). However, intercourse is a matter of pleasure and no one is compelled to it.

Once again, al-Shafi'i is talking about MEN only i.e. intercourse is a matter of pleasure for MEN and they cannot be compelled to it. 

As far as the consent of a slave girl is concerned, then Imam Shafi'i is clear it does not mean anything to her owner. 

And Imam Shafi'i wrote in this book Al-Umm:

وله أن يزوج أمته بغير إذنها بكرا كانت أو ثيبا

“He (i.e. the owner) may marry off his female slave without her consent whether she is a virgin or non-virgin.

Contrary to slave women, the consent of a male slave is needed according to Ahmad bin Hanbal, while Abu Hanifi and Malik say that an owner can coerce male slaves into marriage without their consent. 

Encyclopedia of Islamic Jurisprudence (also known as al-Mawsu'ah al-fiqhiyyah al-Kuwaitiya الموسوعة الفقهیة) writes (link):

لَيْسَ لِلسَّيِّدِ أَنْ يُزَوِّجَ عَبْدَهُ الذَّكَرَ الْبَالِغَ امْرَأَةً لاَ يَرْضَاهَا حُرَّةً كَانَتْ أَوْ أَمَةً، فَإِنْ كَانَ الْعَبْدُ صَغِيرًا جَازَ، وَهَذَا مَذْهَبُ أَحْمَدَ وَقَوْلٌ لِلشَّافِعِيِّ، وَقَال أَبُو حَنِيفَةَ، وَمَالِكٌ: لِلسَّيِّدِ أَنْ يُجْبِرَ عَبْدَهُ عَلَى النِّكَاحِ

A master cannot marry his adult male slave to a woman whom the slave dislikes, whether she is free or a slave. However, if the slave is a minor, it is permissible. This is the view of Ahmad, one opinion within the Shafi'i school. According to  Abu Hanifa and Malik, a master can coerce his slave into marriage.